Wednesday, October 31, 2012

October 31: ORD

Today is October 31st. It's the 305th day of the year. 61 days remain. It's week 44 of the year.   
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire. 

According to the National Climatic Data Center (NCDC), the normal high is 56 and the normal low is 39. I've calculated the 33-year averages at 59 and 41.


On the warm side, in 1979 (O'Hare's second warmest October 31st) the high was 75 with a low of 53. Two years later, in 1981 (O'Hare's third warmest October 31st), the high was 72 with a low of 54. In 1997 the high was 65 with a low of 54. Four years later, in 2001, the high was 68 with a low of 50. In 2008 the high was 70 with a low of 48. In 2000 the high was 70 with a low of 47. The other warm highs were 73 degrees in 1990 and 69 degrees in 1999. The other warm lows were 54 degrees in 1998 and 51 degrees in 1982. The record high of 84 degrees was set in 1950 at Midway. The record warmest low of 65 degrees occurred in 1974 at Midway.
24 of the past 33 highs (73%) were in the: 50s (14) and 60s (10). There were eight consecutive 50s and 60s highs from 1982 through 1989. Additionally, five highs (15%) were in the warm 70s and four (12%) were in the cold 40s. Extremes of the highs happened recently as the high in 2008 was 70 degrees while the high in 2009 was 46 degrees. O'Hare's warmest October 31st was in 1974 as the high was 77 (O'Hare's second hottest high of the date) with a low of 65 (O'Hare's warmest low of the date). The other warm day was in 1968 as the high was 79 (O'Hare's hottest high of the date) with a low of 42. In summary, O'Hare's second warmest lows of the date were 54 degrees in 1981, 1997 and 1998. 

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1974 the high was 77 with a low of 65, a warm day and year of the record warmest low, also 65 at Midway. In 1973 the high was 49 with a low of 42, a seven degree spread. In 1972 the high was 46 with a low of 44, a two degree spread. In 1969 the high was 50 with a low of 47, a three degree spread. In 1968 the high was a warm 79 with a low of 42, a 37 degree spread and warm day. In 1967 the high was 51 with a low of 49, a two degree spread. In 1964 the high was 67 with a low of 29, a 38 degree spread. In 1959 the high was 50 with a low of 46, a four degree spread.


More recently, the
large spread was 31 degrees in 1990 (73/42). There were small spreads of five degrees in 1998 (59/54) and seven degrees in 2005 (57/50).

On the cold side, in 1996 (O'Hare's coolest October 31st) the high was 40 (O'Hare's coolest high of the date) with a low of 26 (O'Hare's co-second coldest low of the date). Three years earlier, in 1993 (O'Hare's second coolest October 31st), the high was 44 (O'Hare's second coolest high of the date) with a low of 25 (O'Hare's coldest low of the date). The other co-second coldest low was 26 degrees in 1988. The record low of 23 degrees and record coldest high of 31 degrees occurred on the same cold, winter-like day way back in 1873, at a time when the official readings were taken adjacent to Lake Michigan. 23 of the last 33 lows (70%) were in the: 30s (11) and 40s (12). There were six consecutive 30s and 40s lows from 2006 through last year, 2011. Three lows (9%) were in the cold 20s. The 20s lows occurred in a nine year span from 1988 through 1996. Seven lows (21%) were in the warm 50s. The most recent 50s low was 50 degrees in 2005. For 14 years (from 1983 through 1996) lows were below 50 degrees. The past six years (from 2006 to 2011) have seen lows below 50 degrees.   

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1996 the high was 40 with a low of 26, overall 14 degrees BELOW normal. Then in 1997 the high was 65 with a low of 54, overall 12.5 degrees ABOVE normal. 

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:57 and sunrise is at 7:26. Sunset is at 17:48 and twilight ends at 18:17. There's a total of 10 hours, 22 minutes of daylight today and 11 hours, 20 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:58 and sunrise is at 7:27. The moon is waning gibbous, having passed the full Hunter's moon two days ago at 14:49. Illumination was 98% at midnight, will be 97% at noon and 95% at midnight tonight. Moonset was at 9:09 this morning. Moonrise is at 18:56 tonight. Moonset is at 10:02 tomorrow morning. Moonlight time is 14 hours, 13 minutes which is 16 minutes longer than yesterday. Moonlight time is near its peak today.

Warm Fall began September 22nd and runs for 41 days through tomorrow, November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is today. Standard Time returns in four days. Election Day is in six days. 

Tuesday, October 30, 2012

October 30: ORD

Today is October 30th. It's the 304th day of the year. 62 days remain. It's week 44 of the year.  
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 57 and the normal low is 39. I've calculated the 33-year averages at 61 and 40.


On the warm side, in 1999 the high was 76 (with 1974, O'Hare's second hottest high of the date) with a low of 56 (O'Hare's co-second warmest low of the date). A decade earlier, in 1989, the high was 75 with a low of 55. In 2004 the high was 72 with a low of 50. In 1990 the high was 73 with a low of 48. In 1998 the high was 65 with a low of 56 (O'Hare's co-second warmest low of the date). In 1981 the high was 75 with a low of 45, a 30 degree spread. The other warm highs were 72 degrees in 1987, 70 degrees in 2003, 70 degrees in 2006, 69 degrees in 1965 and 69 degrees in 1978. The record high of 85 degrees was set in 1950 at Midway. The record warmest low of 62 degrees occurred in 1974 at Midway. 28 of
the past 33 highs (85%) were in the: 50s (8), 60s (12) and 70s (8). Three consecutive years (1983-1985) featured highs in the 50s. For 3 of 4 years, from 1987-1990 and from 2003-2006, highs were in the 70s. The more recent occurrence featured eight consecutive years (2003-2010) of highs in the 60s and 70s. Five highs were in the cold 40s. Our most recent 40s high was 48 degrees in 2002. O'Hare's warmest October 30th was in 1974 as the high was 76 (with 1999, O'Hare's second hottest high of the date) with a low of 62 (O'Hare's warmest and only 60s low of the date). O'Hare's second warmest October 30th was in 1971 as the high was 80 (O'Hare's hottest and only 80s high of the date) with a low of 55. The other warm low of 51 degrees occurred in 1960. 

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was a warm 69 degrees. In 1976 the high was 49 with a low of 42, a seven degree spread. In 1974 the high was 76 with a low of 62, a warm day. 1974 was also the year of the record warmest low, also of 62 at Midway. In 1971 the high was 80 with a low of 55, a warm day. In 1968 the low was a cold 27 degrees. In 1966 the high was 52 with a cold low of 22, a 30 degree spread. In 1965 the high was a warm 69 degrees. In 1964 the high was 58 with a cold low of 24, a 34 degree spread. In 1963 the high was 58 with a cold low of 27, a 31 degree spread. In 1960 the low was a warm 51 degrees. 


More recently, there were large spreads of 36 degrees in 1987 (72/36), 32 degrees in 2006 (70/38), 31 degrees three years ago, in 2008 (62/31) and 30 degrees in 2003 (70/40). There were small spreads of four degrees in 1992 (46/42), five degrees in 1995 (45/40), five degrees in 2001 (52/47) and seven degrees in 2002 (48/41).

On the cold side, in 1988 (O'Hare's coolest October 30th) the high was 45 with the record low of 21. Five years later, in 1993 (O'Hare's second coolest October 30th), the high was 40 (O'Hare's coolest high of the date) with a low of 30. The other cold lows were 22 degrees in 1966 (O'Hare's second coldest low), 24 degrees in 1964, 24 degrees in 1980, 27 degrees in 1963 and 27 degrees in 1968. The other cold high was 45 degrees in 1995. The record coldest high of 28 degrees occurred back in 1917, at a time when the official readings were taken adjacent to Lake Michigan. 26 of the last 33 lows (79%) were in the: 30s (14) and 40s (12). Lows were in the 30s and 40s for: eight consecutive years from 1990 through 1997 and seven consecutive years from 2005 through last year, 2011. Two lows (6%) were in the cold 20s. The 20s lows occurred in the 1980s (24 degrees in 1980 and the record low of 21 degrees in 1988). Five lows (15%) were in the warm 50s, most recently 50 degrees in 2004.

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1988 the high was 45 with a low of 21, overall 15 degrees BELOW normal. Then in 1989 the high was 75 with a low of 55, overall 17 degrees ABOVE normal. 

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:56 and sunrise is at 7:25. Sunset is at 17:49 and twilight ends at 18:18. There's a total of 10 hours, 24 minutes of daylight today and 11 hours, 22 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:57 and sunrise is at 7:26. The moon is waning gibbous, having passed the full Hunter's moon yesterday at 14:49. Illumination was 100% at midnight, will be 99% at noon and 98% at midnight tonight. Moonset was at 8:13 this morning. Moonrise is at 18:16 tonight. Moonset is at 9:09 tomorrow morning. Moonlight time is 13 hours, 57 minutes which is 24 minutes longer than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is tomorrow. Standard Time returns in five days. Election Day is in seven days.   

October 29: ORD

Today is October 29th. It's the 303rd day of the year. 63 days remain. It's week 44 of the year.  
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 57 and the normal low is 39. I've calculated the 33-year averages at 58 and 39.

On the warm side, in 2004 (O'Hare's warmest October 29th) the high was 76 (O'Hare's second hottest high of the date) with a low of 61 (O'Hare's warmest low of the date). The low was also 61 degrees in 1900. In 1989 (O'Hare's second warmest October 29th) the high was 74 with a low of 54. A couple of years later, in 1991, the high was 70 with a low of 55. In 1999 the high was the record high of 78 with a low of 45, a 33 degree spread. The other warm highs were 72 degrees in 1971 and 69 degrees in 1979.
The record warmest low of 65 degrees was set in 1946 at Midway. 23 of the past 33 highs (70%) were in the: 50s (12) and 60s (11). Highs were in the 50s and 60s for: seven consecutive years from 1981 through 1987 and seven consecutive years from 2005 through last year, 2011. Four highs (12%) were in the warm 70s. Six highs (18%) were in the cold: 30s (1) and 40s (5). The last highs in the 40s and 70s came in back to back years (48 degrees in 2003 and 76 degrees in 2004). O'Hare's other warm days occurred in: 1961 (high of 70, low of 55) and 1974 (high of 64 and O'Hare's second warmest low of the date of 57). The other warm low of 51 degrees occurred in 1960.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1974 the high was 64 with a warm low of 57, a seven degree spread and warm day. In 1973 the high was 49 with a low of 44, a five degree spread. In 1971 the high was a warm 72 degrees. In 1966 the high was 48 with a cold low of 24, a cool day. In 1965 the high was 55 with a cold low of 22 degrees, a 33 degree spread. In 1964 the low was a cold 27 degrees. In 1963 the high was 57 with a cold low of 27, a 30 degree spread. In 1961 the high was 70 with a low of 55, a warm day. In 1960 the high was 58 with a warm low of 51, a seven degree spread.


More recently, there were additional
large spreads of 33 degrees in 2005 (61/28), 31 degrees in 1984 (61/30) and 30 degrees in 1990 (60/30). There were small spreads of four degrees in 2002 (46/42) and six degrees in 1992 (48/42).

On the cool side, in 1988 (O'Hare's coolest October 29th) the high was 41 (O'Hare's second coolest high of the date) with a low of 25. Five years later, in 1993 (O'Hare's second coolest October 29th), the high was 39 (O'Hare's coolest and only 30s high of the date) with a low of 30. In 1980 the high was 47 with a low of 25. Those lows of 25 degrees (1980 and 1988) are O'Hare's co-third coldest lows. The record low of 19 degrees and record coolest high of 29 degrees were set on the same cold day back in 1925, at a time when the official readings were taken adjacent to Lake Michigan. 26 of the last 33 lows (79%) were in the: 30s (14) and 40s (12). Lows were in the 30s and 40s for: seven consecutive years from 1981 through 1987, six consecutive years from 1998 through 2003 and six consecutive years from 2006 through last year, 2011. Four lows (12%) were in the cold 20s. Three lows (9%) were in the warm: 50s (2) and 60s (1). The last lows in the 60s and 20s came in back to back years (61 degrees in 2004 and 28 degrees in 2005). O'Hare's other cool day was in 1966 (high of 48 and O'Hare's second coldest low of the date of 24). O'Hare's other cold lows are 22 degrees in 1965 (O'Hare's coldest low of the date) and 27 degrees in 1963.

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1988 the high was 41 with a low of 25, overall 15 degrees BELOW normal. Then in 1989 the high was 74 with a low of 54, overall 16 degrees ABOVE normal. 

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:54 and sunrise is at 7:23. Sunset is at 17:50 and twilight ends at 18:19. There's a total of 10 hours, 27 minutes of daylight today and 11 hours, 25 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:56 and sunrise is at 7:25. The moon reaches the full Hunter's moon today at 14:49. Illumination was 100% at midnight, will be 100% at noon and 100% at midnight tonight. Moonset was at 7:14 this morning. Moonrise is at 17:41 this afternoon. Moonset is at 8:13 tomorrow morning. Moonlight time is 13 hours, 33 minutes which is 27 minutes longer than yesterday. 

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is in two days. Standard Time returns in six days. Election Day is in eight days. 

Sunday, October 28, 2012

October 28: ORD

Today is October 28th. It's the 302nd day of the year. 64 days remain. It's week 44 of the year.
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 58 and the normal low is 39. I've calculated the 33-year averages at 58 and 39.


On the warm side, in 1999 (O'Hare's warmest October 28th) the high was the record high of 80 (Chicago's only 80s high of the date) with a low of 48, a 32 degree spread. A decade earlier, in 1989 (O'Hare's second warmest October 28th), the high was 74 (O'Hare's second hottest high of the date and our most recent 70s high) with a low of 53 (O'Hare's second warmest low of the date). In 1982 the high was 70 with a low of 54 (O'Hare's warmest low of the date). The other warm highs are 73 degrees in 1966, 73 degrees in 1983 and 71 degrees in 1986. As you can see, all of the post-1978 70s highs occurred between 1982 and 1989. The other warm low of 52 degrees occurred in 1991. The record warmest low of 58 degrees was set way back in 1896
, at a time when the official readings were taken adjacent to Lake Michigan. 15 of the past 33 highs (46%) were in the 50s. 12 highs (36%) were in the warm: 60s (7), 70s (4) and 80s (1). Six highs (18%) were in the cool 40s. Our most recent 60s high was 61 degrees in 2004. The other warm day was in 1974 as the high was 73 with a low of 50.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1976 the high was 49 with a cold low of 22, a cool day. In 1974 the high was a warm 73 with a low of 50, a warm day. In 1969 the high was 45 with a low of 25, a cold day. In 1968 the high was a cold 44 with a low of 39, a five degree spread. In 1967 the high was a cold 46 degrees. In 1966 the high was a warm 73 with a low of 37, a 36 degree spread. In 1965 the high was 48 with a cold low of 24, a cool day. In 1960 the high was 56 with a low of 49, a seven degree spread. In 1959 the high was 43 with a low of 25, a cold day.


More recently, there were
additional large spreads of 34 degrees in 1981 (65/31) and 30 degrees in 1983 (73/43). There were small spreads of six degrees in 1991 (58/52), seven degrees in 2000 (53/46), seven degrees three years ago, in 2009 (57/50) and seven degrees two years ago, in 2010 (46/39).

On the cool side, in 1980 (tied with 1969 as O'Hare's second coolest October 28th) the high was 44 with a low of 26. In 1988 the high was 44 with a low of 30. O'Hare's second coolest highs of the date (44 degrees) were those just mentioned (in 1980 and 1988) and in 1968. The other cold low of 25 degrees occurred in 1997. The other cool highs were 45 degrees in 2008, 46 degrees in 1967 and 46 degrees two years ago in 2010. The record low of 19 degrees and record coolest high of 31 degrees were set on the same cold day back in 1925, at a time when the official readings were taken adjacent to Lake Michigan. 27 of the last 33 lows (82%) were in the: 30s (17) and 40s (10). Our most recent 40s low was 46 degrees in 2004. Two lows were in the cold 20s. Four lows were in the warm 50s, three of them occurring in a ten year span from 1982 through 1991. O'Hare's coolest October 28th was in 1959 as the high was 43 (O'Hare's coolest high of the date) with a low of 25. Tied with 1980 as O'Hare's second coolest October 28th is 1969 (high of 45, low of 25). O'Hare's other cool 10/28 days are: 1976 (high of 49, low of 22) and 1965 (high of 48, low of 24 (O'Hare's second coldest low of the date)).  

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:53 and sunrise is at 7:22. Sunset is at 17:51 and twilight ends at 18:20. There's a total of 10 hours, 29 minutes of daylight today and 11 hours, 27 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:54 and sunrise is at 7:23. The moon is waxing gibbous, heading towards the full Hunter's moon tomorrow at 14:49. Illumination was 98% at midnight, will be 99% at noon and 100% at midnight tonight. Moonset was at 6:15 this morning. Moonrise is at 17:09 this afternoon. Moonset is at 7:14 tomorrow morning. Moonlight time is 13 hours, 6 minutes which is 32 minutes longer than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is in three days. Standard Time returns in seven days. Election Day is in nine days. 

Saturday, October 27, 2012

October 27: ORD

Today is October 27th. It's the 301st day of the year. 65 days remain. It's week 43 of the year. 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980.
Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.
 

According to the National Climatic Data Center (NCDC), the normal high is 58 and the normal low is 40. I've calculated the 33-year averages at 58 and 40.


On the warm side, in 1984 (O'Hare's warmest October 27th) the high was 76 (O'Hare's co-hottest high of the date) with the record warmest low of 63. In 1998 the high was 70 with a low of 56. In 1989 the high was 76 (O'Hare's other co-hottest high of the date) with a low of 49. In 2000 the high was 71 (our most recent 70s high) with a low of 51. The other warm highs were 72 degrees in 1974 and 70 degrees in 1966. The other warm lows were 53 degrees in 2004 and 52 degrees in 1996. The record high of 83 degrees was set back in 1927
at the University of Chicago. 28 of the past 33 highs (85%) were in the: 40s (7), 50s (10) and 60s (11). Four highs were in the warm 70s. One high was in the cold 30s (O'Hare's only 30s high of 38 degrees in 1997). There have been no highs in the 80s in the history of O'Hare on this date! O'Hare's second warmest October 27th was in 1971 as the high was 74 (O'Hare's second hottest high of the date) with a low of 54. O'Hare's other warm 10/27 was in 1970 as the high was 67 with a low of 60 (O'Hare's second warmest low of the date). 

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1976 the high was 42 with a low of 23, a cold day. In 1974 the high was a warm 72 with a low of 38, a 34 degree spread. In 1971 the high was 74 with a low of 54, a warm day. In 1970 the high was 67 with a warm low of 60, a seven degree spread and warm day. In 1969 the high was 44 with a low of 28, a cold day. In 1967 the high was a cold 41 with a low of 34, a seven degree spread and cool day. In 1966 the high was a warm 70 degrees. In 1962 the high was 64 with a low of 34, a 30 degree spread. In 1961 the low was a cold 25 degrees. In 1959 the high was a cold 40 with a low of 33, a seven degree spread and cool day.


More recently, there were large spreads of 33 degrees in 1983 (65/32) and 32 degrees in 1982 (65/33). There were small spreads of six degrees in 1991 (53/47), six degrees three years ago, in 2009 (51/45), and seven degrees in 2006 (45/38).

On the cool side, in 1997 (O'Hare's coolest October 27th) the high was 38 (O'Hare's coolest high of the date) with a low of 26. In 1980 the high was 43 with a low of 27. In 2001 the high was 45 with a low of 30. The other cold low was O'Hare's second coldest low of 25 degrees in 1961. The other cold highs were 44 degrees in 2003, 45 degrees in 2006, 46 degrees in 1993 and 46 degrees in 2002. The record low of 24 degrees was set in 1942 at Midway. The record coolest high of 34 degrees was set in 1925, at a time when the official readings were taken adjacent to Lake Michigan. 17 of the last 33 lows (52%) were in the 30s. 14 lows (42%) were in the: 40s (9), 50s (4) and 60s (1). The four lows in the 50s occurred in a nine year span from 1996 through 2004. The lone 60s low is the current record warmest low of 63 degrees in 1984. Two lows (6%) were in the cold 20s (27 degrees in 1980 and 26 degrees in 1997). O'Hare's second coolest October 27th was in 1976 as the high was 42 with a low of 23 (O'Hare's coldest low of the date and a low that's colder than the record low). The other cool days were in: 1969 (high of 44, low of 28), 1959 (high of 40 (O'Hare's second coolest high of the date), low of 33)) and 1967 (high of 41, low of 34).   

There's two instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1997 the high was 38 with a low of 26, overall 17 degrees BELOW normal. Then in 1998 the high was 70 with a low of 56, overall 14 degrees ABOVE normal. In the second instance, in 2000 the high was 71 with a low of 51, overall 12 degrees ABOVE normal. Then in 2001 the high was 45 with a low of 30, overall 11.5 degrees BELOW normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:52 and sunrise is at 7:21. Sunset is at 17:53 and twilight ends at 18:22. There's a total of 10 hours, 32 minutes of daylight today and 11 hours, 30 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:53 and sunrise is at 7:22. The moon is waxing gibbous, heading towards the full Hunter's moon in two days at 14:49. Illumination was 94% at midnight, will be 96% at noon and 98% at midnight tonight. Moonset was at 5:14 this morning. Moonrise is at 16:40 this afternoon. Moonset is at 6:15 tomorrow morning. Moonlight time is 12 hours, 34 minutes which is 33 minutes longer than yesterday.  

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is in four days. Standard Time returns in eight days. Election Day is in ten days. 

Friday, October 26, 2012

October 26: ORD

Today is October 26th. It's the 300th day of the year. 66 days remain. It's week 43 of the year. 
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.
 

According to the National Climatic Data Center (NCDC), the normal high is 58 and the normal low is 40. I've calculated the 33-year averages at 57 and 41.

On the warm side, in 2000 (tied with 1971 as O'Hare's warmest October 26th) the high was 76 (O'Hare's third hottest high of the date) with a low of 59 (O'Hare's warmest low of the date). In 1989 the high was 75 with a low of 50. In 1996 the high was 68 with a low of 56 (O'Hare's third warmest low of the date). Two years ago, in 2010, the high was 70 (occurred early in the morning) with a low of 54. In 1998 the high was 73 with a low of 50. The other warm highs were 72 degrees in 1964 and 70 degrees in 1985. The other warm lows were 53 degrees in 2004, 53 degrees in 2007 and 52 degrees in 1986. The record high of 84 degrees was set in 1963 at Midway. The record warmest low of 63 degrees was set back in 1939 at the University of Chicago
. 21 of the past 33 highs (64%) were in the: 50s (13) and 60s (8). There were seven consecutive highs in the 50s and 60s from 1990 through 1996. Our most recent 60s high was 60 degrees in 2004. Five highs (15%) were in the warm 70s. Seven highs (21%) were in the cold 40s. Three consecutive years had highs in the 40s: 41 degrees in 2001, 47 degrees in 2002 and 45 degrees in 2003. 1971 is tied with 2000 as O'Hare's warmest October 26th. In 1971 the high was 78 (O'Hare's second hottest high of the date) and low of 57 (O'Hare's second warmest low of the date). O'Hare's second warmest 10/26 was in 1963 as the high was 83 (O'Hare's hottest and only 80s high of the date) with a low of 45. The other warm day was in 1970 (high of 72, low of 52).

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1974 the high was 66 with a low of 34, a 32 degree spread. In 1971 the high was 78 with a low of 57, a warm day. In 1970 the high was 72 with a low of 52, a warm day. In 1966 the high was 62 with a cold low of 25, a 37 degree spread. In 1964 the high was a warm 72 degrees. In 1963 the high was a warm 83 with a low of 45, a 38 degree spread, warm day and year of the record high of 84 at Midway. In 1962 the high was 45 with a low of 19 (colder than the record low of 22), a cold day. In 1961 the low was a cold 28 degrees. In 1959 the high was a cold 39 with a low of 34, a five degree spread and cold day.


More recently, there was a large spread of 33 degrees in 1982 (64/31). There were small spreads of three degrees in 2006 (46/43), five degrees in 2001 (41/36), six degrees three years ago, in 2009 (55/49), seven degrees in 1986 (59/52), seven degrees in 1991 (54/47) and seven degrees in 2004 (60/53).

On the cool side, in 1980 (O'Hare's second coolest October 26th) the high was 42 (O'Hare's third coolest high of the date) with a low of 26 (O'Hare's third coldest low of the date). In 1988 the high was 44 with a low of 28. The other cool highs were 41 degrees in 2001 (O'Hare's second coolest high of the date), 45 degrees in 2003, 46 degrees in 1997 and 46 degrees in 2006. The other cold lows were 25 degrees in 1966 (O'Hare' second coldest low of the date), 27 degrees in 1979, 28 degrees in 1961 and 28 degrees in 1990. The record low of 22 degrees and record coolest high of 37 degrees were set on the same cold day back in 1942 at Midway. That record low of 22 degrees was originally set way back in 1887. 13 of the last 33 lows (39%) were in the 30s. Some of the 30s lows occurred in two streaks: 1. 33 degrees in 1981, 31 degrees in 1982 and 32 degrees in 1983 and 2. 36 degrees in 2001, 38 degrees in 2002 and 35 degrees in 2003.  Four lows (12%) were in the cold 20s. The 20s lows occurred in two clusters: 1. 27 and 26 degrees in 1979 and 1980 and 2. 28 degrees in both 1988 and 1990 (our most recent 20s low). 16 lows (49%) were in the warm: 40s (8) and 50s (8). O'Hare's coolest October 26th was in 1962 as the high was 45 with a low of 19 (O'Hare's coldest low of the date and a low that's colder than the record low). The other cool day was in 1959 as the high was 39 (O'Hare's coolest high of the date) and low of 34.

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1988 the high was 44 with a low of 28, overall 13 degrees BELOW normal. Then in 1989 the high was 75 with a low of 50, overall 13.5 degrees ABOVE normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:51 and sunrise is at 7:20. Sunset is at 17:54 and twilight ends at 18:23. There's a total of 10 hours, 34 minutes of daylight today and 11 hours, 32 minutes between twilights. We lost four minutes of daylight from yesterday. Tomorrow twilight begins at 6:52 and sunrise is at 7:21. The moon is waxing gibbous, heading towards the full Hunter's moon in three days at 14:49. Illumination was 88% at midnight, will be 91% at noon and 94% at midnight tonight. Moonset was at 4:13 this morning. Moonrise is at 16:12 this afternoon. Moonset is at 5:14 tomorrow morning. Moonlight time is 12 hours, 1 minute which is 36 minutes longer than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is in five days. Standard Time returns in nine days. Election Day is in 11 days.  

Thursday, October 25, 2012

October 25: ORD

Today is October 25th. It's the 299th day of the year. 67 days remain. It's week 43 of the year.
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.
 

According to the National Climatic Data Center (NCDC), the normal high is 59 and the normal low is 40. I've calculated the 33-year averages at 58 and 39.


On the warm side, in 1989 (O'Hare's warmest October 25th) the high was 77 (tied with 1989 as O'Hare's hottest high of the date) with a low of 52. Two years ago, in 2010 (tied with 1963 and 1971 as O'Hare's second warmest October 25ths), the high was 72 with a low of 56 (O'Hare's second warmest low of the date). In 2000 the high was 69 with a low of 55. The other hot highs were 76 degrees in 1964 (O'Hare's second hottest high of the date), 75 degrees in 2004 and 74 degrees last year, in 2011. The other warm low was 52 degrees in 1986. The record high of 79 degrees and record warmest low of 62 degrees were set in on the same warm day in 1963
at Midway. 27 of the past 33 highs (82%) were in the: 40s (7), 50s (10) and 60s (10). Our most recent 40s highs were 40 degrees in 2001 and 47 degrees in 2002. Five highs were in the warm 70s. One high was in the cold 30s. There were no 80s highs on this date in O'Hare's history or in the history of Chicago record-keeping. The two years that are tied with 2010 as O'Hare's second warmest October 25ths are 1963 (high of 77 (tied with 1989 as O'Hare's hottest high of the date), low of 51) and 1971 (high of 69, low of 59 (O'Hare's warmest low of the date)). 

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1971 the high was 69 with a warm low of 59, a warm day. In 1967 the high was a cold 44 with a low of 38, a six degree spread. In 1966 the high was 57 with a cold low of 26, a 31 degree spread. In 1964 the high was a warm 76 with a low of 41, a 35 degree spread. In 1963 the high was a warm 77 with a low of 51, a warm day and year of the record high of 79 and record warmest low of 62 (records set at Midway). In 1962 the high was 38 with a low of 21, a cold day. In 1959 the high was a cold 40 with a low of 35, a five degree spread and cold day. 


More recently, there was a large spread of 37 degrees in 2004 (75/38), 36 degrees in 1982 (62/26), 31 degrees in 1985 (67/36), 30 degrees in 1996 (68/38) and 30 degrees in 1999 (65/35). There were small spreads of three degrees in 1986 (55/52), four degrees in 1997 (49/45), five degrees in 1994 (46/41) and five degrees in 2002 (47/42).

On the cold side, in 1988 (O'Hare's second coolest October 25th) the high was 43 with a low of 26. In 1980 the high was 39 (O'Hare's second coolest high of the date) with a low of 33, a six degree spread. In 2001 the high was 40 with a low of 35, a five degree spread. In 1979 the high was 46 with a low of 31. The other cold lows were 26 degrees in both 1966 and 1982. The other cool highs were 44 degrees in 1967, 45 degrees in 1981, 46 degrees in 1994 and 47 degrees in 2002. The record low of 14 degrees and record coldest high of 29 degrees were set on the same cold day way back in 1887, at a time when the official readings were taken adjacent to Lake Michigan. 25 of the last 33 lows (76%) were in the: 30s (14) and 40s (11). There were ten consecutive 30s and 40s lows from 1990 through 1999. Our most recent 30s lows were each 38 degrees in 2004 and 2005. Four lows (12%) were in the cold 20s. Four lows (12%) were in the warm 50s. O'Hare's coolest October 25th was in 1962 as the high was 38 (O'Hare's coolest high of the date) and low of 21 (O'Hare's coldest low of the date). Another cool day was in 1959 as the high was 40 with a low of 35. To summarize, O'Hare's second coldest lows were 26 degrees in 1966, 1982 and 1988.

There's two instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1988 the high was 43 with a low of 26, overall 15.5 degrees BELOW normal. Then in 1989 the high was 77 with a low of 52, overall 14.5 degrees ABOVE normal. In the second instance, in 2000 the high was 69 with a low of 55, overall 12 degrees ABOVE normal. Then in 2001 the high was 40 with a low of 35, overall 12.5 degrees BELOW normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:50 and sunrise is at 7:18. Sunset is at 17:56 and twilight ends at 18:24. There's a total of 10 hours, 38 minutes of daylight today and 11 hours, 34 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:51 and sunrise is at 7:20. The moon is waxing gibbous. Illumination was 81% at midnight, will be 85% at noon and 88% at midnight tonight. Moonset was at 3:10 this morning. Moonrise is at 15:45 this afternoon. Moonset is at 4:13 tomorrow morning. Moonlight time is 11 hours, 25 minutes which is 35 minutes longer than yesterday. 

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. Halloween is in six days. Standard Time returns in ten days. Election Day is in 12 days. 

Wednesday, October 24, 2012

October 24: ORD

Today is October 24th. It's the 298th day of the year. 68 days remain. It's week 43 of the year. 
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.
 

According to the National Climatic Data Center (NCDC), the normal high is 59 and the normal low is 41. I've calculated the 33-year averages at 57 and 40.


On the warm side, in 1991 (O'Hare's warmest October 24th) the high was 74 with the record warmest low of 63. Two years prior, in 1989, the high was 76 (O'Hare's third hottest high) with a low of 51. Two years ago, in 2010, the high was 72
with a low of 54. In 2000 the high was 67 with a low of 58. The other warm highs were 74 degrees in 1975, 71 degrees in 1974 and 71 degrees in 1985. We went 19 years, from 1991 to 2010, between highs in the 70s. The other warm low was 54 degrees in 1986. The record high of 83 degrees was set in 1963 at Midway. 22 of the past 33 highs (67%) were in the: 50s (13) and 60s (9). Four highs (12%) were in the warm 70s. Seven highs (21%) were in the cold 40s. O'Hare's second warmest October 24th was in 1963 as the high was 82 (O'Hare's hottest high of the date) with a low of 53. O'Hare's other warm days were in: 1973 (high of 78 (O'Hare's second hottest high of the date), low of 53)), 1970 (high of 72, low of 53) and 1971 (high of 64, low of 61 (O'Hare's second warmest low of the date)). UPDATE: O'Hare had a high of 78 degrees today (10/24/12) which ties 1973 as the second hottest high of the date.  

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1976 the high was 49 with a low of 43, a six degree spread. In 1975 the high was a warm 74 with a low of 47, a warm day. In 1974 the high was a warm 71 degrees. In 1973 the high was 78 with a low of 53, a warm day. In 1972 the high was a cold 42 with a low of 40, a two degree spread. In 1971 the high was 64 with a warm low of 61, a three degree spread and warm day. In 1970 the high was 72 with a low of 53, a warm day. In 1966 the high was 60 with a cold low of 28, a 32 degree spread. In 1964 the high was 62 with a cold low of 24, a 38 degree spread. In 1963 the high was 82 with a low of 53, a warm day and year of the record high of 83 at Midway. In 1962 the high was 45 with a low of 25, a cold day. In 1960 the high was 43 with a low of 29, a cold day.


More recently, there was a
large spread of 34 degrees in 1982 (57/23). There were small spreads of four degrees in 1983 (51/47), four degrees in 1986 (58/54), four degrees in 2002 (46/42) and six degrees in 1997 (49/43).

On the cool side, in 1981 (O'Hare's coolest October 24th) the high was the co-record coolest high of 40 with the record low of 17. In 1988 (O'Hare's second coolest October 24th) the high was the co-record coolest high of 40 with a low of 26. The other cold lows were 23 degrees in 1982 (O'Hare's second coldest low of the date), 24 degrees in 1964 (O'Hare's third coldest low of the date), 28 degrees in 1966, 28 degrees in 1984 and 28 degrees in 1999 (our most recent 20s low). The other cool highs are 42 degrees in 1972 (O'Hare's second coolest high of the date) and 46 degrees in 2002. 23 of the last 33 lows (70%) were in the: 30s (9) and 40s (14). There were two long stretches of lows in the 30s and 40s. The first was seven years from 1992 through 1998. The second was nine years from 2001 through 2009. Five lows (15%) were in the cold: 10s (1) and 20s (4).  Five lows (15%) were in the warm: 50s (4) and 60s (1). O'Hare's other cool days were in: 1962 (high of 45, low of 25) and 1960 (high of 43, low of 29).

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1988 the high was 40 (the record coldest high) with a low of 26, overall 17 degrees BELOW normal. Then in 1989 the high was 76 with a low of 51, overall 13.5 degrees ABOVE normal.


The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:49 and sunrise is at 7:17. Sunset is at 17:57 and twilight ends at 18:26. There's a total of 10 hours, 40 minutes of daylight today and 11 hours, 37 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:50 and sunrise is at 7:18. The moon is waxing gibbous. Illumination was 72% at midnight, will be 77% at noon and 81% at midnight tonight. Moonset was at 2:07 this morning. Moonrise is at 15:17 this afternoon. Moonset is at 3:10 tomorrow morning. Moonrise is at 15:45 tomorrow afternoon. Moonlight time is 10 hours, 50 minutes which is 36 minutes longer than yesterday. 

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is today. Halloween is in seven days. Standard Time returns in 11 days. Election Day is in 13 days.

Tuesday, October 23, 2012

October 23: ORD

Today is October 23rd. It's the 297th day of the year. 69 days remain. It's week 43 of the year.
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 60 and the normal low is 41. I've calculated the 33-year averages at 59 and 42.


On the warm side, in 1992 the high was 76 with a low of 58. The year before, in 1991, the high was 77 with a low of 55. In 2004 the high was 76 (our most recent 70s high) with a low of 55. In 2000 the high was 71 with a low of 58. The following year of 2001 saw a  high of 65 with a low of 58, a seven degree spread. Those lows of 58 degrees in 1992, 2000 and 2001 are O'Hare's second warmest lows of the date. The other warm lows are 57 degrees in 1971, 55 degrees in 1986 and 54 degrees in: 1970, 1985 and two years ago, in 2010. The other warm highs were 75 degrees in 1973, 72 degrees in 1989 and 71 degrees in 1995. The record high of 85 degrees was set in 1963 at Midway
. The record warmest low of 64 degrees occurred back in 1920, at a time when the official readings were taken adjacent to Lake Michigan. 26 of the past 33 highs (79%) were in the: 40s (7), 50s (9) and 60s (10). O'Hare recorded consecutive highs in the 40s, 50s and 60s as: seven from 1982 through 1988 and seven from 2005 through last year, 2011. Six highs (18%) were in the warm 70s. One high (3%) was in the cold 30s (the record coolest high of 35 degrees in 1981). O'Hare's warmest October 23rd was in 1963 as the high was 85 (O'Hare's hottest and only 80s high of the date) with a low of 55. O'Hare's second warmest 10/23 was in 1975 as the high was 78 (with 1967, O'Hare's second warmest high of the date) with a low of 60 (O'Hare's warmest and only 60s low of the date). The other warm 10/23 was in 1967 as the high was 78 (with 1975, O'Hare's second warmest high of the date) and low of 54.    

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1975 the high was 78 with a low of 60, a warm day. In 1973 the high was a warm 75 with a low of 45, a 30 degree spread. In 1971 the high was 62 with a warm low of 57, a five degree spread. In 1970 the low was a warm 54 degrees. In 1969 the high was 48 with a low of 25, a cold day. In 1967 the high was 78 with a low of 54, a warm day. In 1964 the high was 53 with a cold low of 22 degrees, a 31 degree spread and a cool day. In 1963 the high was 85 with a low of 55, a 30 degree spread, a hot day and year of the record high, also of 85 at Midway. In 1963, 4 of 5 days from the 22nd to the 26th, highs were in the 80s. In 1962 the high was 47 with a low of 29, a cold day.


More recently, there were additional large spreads of 30 degrees in 1989 (72/42), 30 degrees in 1993 (68/38) and 30 degrees last year, in 2011 (68/38). There were additional small spreads of five degrees in 1983 (52/47), six degrees in 1979 (45/39) and six degrees in 2002 (46/40).

On the cool side, in 1981 (O'Hare's coolest October 23rd) the high was the record coolest high of 35 (O'Hare's only 30s high of the date) with the record low of 20. In the following year of 1982, the high was 54 with a low of 23 (O'Hare's third coldest low of the date). The other cold lows were 28 degrees in 1984 and 29 degrees in 1987. The other cool highs were 45 degrees in 1979, 46 degrees in 2002, 48 degrees in 1996 and 48 degrees in 2005. 29 of the last 33 lows (88%) were in the: 30s (11), 40s (10) and 50s (8). Four lows  were in the cold 20s. These 20s lows occurred within a span of seven years from 1981 to 1987. O'Hare's second coolest October 23rd was in 1969 as the high was 48 with a low of 25. The other cool days are 1964 (high of 53, low of 22 (O'Hare's second coldest low of the date)) and 1962 (high of 47, low of 29).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:47 and sunrise is at 7:16. Sunset is at 17:58 and twilight ends at 18:27. There's a total of 10 hours, 42 minutes of daylight today and 11 hours, 40 minutes between twilights. We lost three minutes of daylight from yesterday. Tomorrow twilight begins at 6:49 and sunrise is at 7:17. The moon is waxing gibbous, having reached first quarter two days ago at 22:32. Illumination was 62% at midnight, will be 67% at noon and 72% at midnight tonight. Moonset was at 1:01 this morning. Moonrise is at 14:47 this afternoon. Moonset is at 2:07 tomorrow morning. Moonrise is at 15:17 tomorrow afternoon. Moonlight time is 10 hours, 14 minutes which is 28 minutes longer than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is tomorrow. Halloween is in eight days. Election Day is in 14 days. Standard Time doesn't return until November 4th.

October 22: ORD

Today is October 22nd. It's the 296th day of the year. 70 days remain. It's week 43 of the year.
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 60 and the normal low is 41. I've calculated the 33-year averages at 60 and 39.


On the warm side, in 1991 the high was 76 with a low of 50. Five years prior, in 1986, the high was 75 with a low of 50. The other warm highs were 76 degrees in 1979, 73 degrees in 1992, 72 degrees in 1967 and 72 degrees in 1994 (our most recent 70s high). The record high of 87 degrees was set in 1953
at Midway. The record warmest low of 66 degrees occurred back in 1920, at a time when the official readings were taken adjacent to Lake Michigan. 25 of the past 33 highs (76%) were in the: 50s (14) and 60s (11). A long, eight year stretch of years from 1998 through 2005 had highs in the 50s and 60s. Five highs (15%) were in the warm 70s. Three highs (9%) were in the cold 40s. The 70s highs, as noted above, occurred from 1979 to 1994. The most recent three occurred in a four year period from 1991 to 1994. O'Hare's warmest October 22nd was in 1963 as the high was 84 (O'Hare's hottest high of the date) with a low of 59 (O'Hare's co-warmest low of the date). O'Hare's second warmest October 22nd was in 1971 as the high was 71 with a low of 59 (O'Hare's other co-warmest low of the date). The other warm 10/22 days were: 1975 (high of 80 (O'Hare's second hottest high of the date) and low of 46) and 1978 (high of 73 and low of 52).
 
In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was a warm 73 with a low of 52, a warm day. In 1976 the high was 47 with a low of 25, a cold day. In 1975 the high was a warm 80 with a low of 46, a warm day. In 1973 the high was 71 with a low of 39, a 32 degree spread. In 1971 the high was 71 with a warm low of 59, a warm day. In 1969 the high was a cold 43 with a low of 31, a cold day. In 1967 the high was a warm 72 with a low of 35, a 37 degree spread. In 1964 the low was a cold 28 degrees. In 1963 the high was 84 (O'Hare's warmest) with a low of 59, a warm day.


More recently, there were large spreads of 33 degrees in 1989 (64/31), 31 degrees in 1979 (76/45), 31 degrees in 1992 (73/42) and 31 degrees last year, in 2010 (64/33). There was a small spread of six degrees in 1983 (55/49). 

On the cool side, in 1982 (O'Hare's coolest October 22nd) the high was 49 with the record low of 22. In 1997 the high was 44 (O'Hare's second coolest high of the date) with a low of 29. The record coolest high of 41 degrees occurred back in 1913, at a time when the official readings were taken adjacent to Lake Michigan. 29 of the last 33 lows (88%) were in the: 30s (16) and 40s (13). Two lows were in the cold 20s. Two lows were in the warm 50s. O'Hare's second coolest October 22nd was in 1976 as the high was 47 with a low of 25 (O'Hare's second coldest low of the date). Another cool day was in 1969 as the high was 43 (O'Hare's coolest high of the date) and low of 31. The other cold low of 28 degrees occurred in 1964.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:46 and sunrise is at 7:15. Sunset is at 18:00 and twilight ends at 18:29. There's a total of 10 hours, 45 minutes of daylight today and 11 hours, 43 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:47 and sunrise is at 7:16. The moon is waxing gibbous, having reached first quarter yesterday at 22:32. Illumination was 51% at midnight, will be 57% at noon and 62% at midnight tonight. Moonrise is at 14:14 this afternoon. Moonset is at 1:01 tomorrow morning. Moonrise is at 14:47 tomorrow afternoon. Moonlight time is 9 hours, 46 minutes which is 32 minutes shorter than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is in two days. Halloween is in nine days. Election Day is in 15 days. Standard Time doesn't return until November 4th.  

October 21: ORD

Today is October 21st. It's the 295th day of the year. 71 days remain. It's week 42 of the year.
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 60 and the normal low is 41. I've calculated the 33-year averages at 60 and 43.


On the warm side, in 1979 (O'Hare's warmest October 21st) the high was 84 (O'Hare's hottest high of the date) with a low of 70 (O'Hare's warmest low of the date). The record warmest low of 70 degrees was set in 1979 at Midway. In 2007 (O'Hare's second warmest October 21st) the high was 80 (O'Hare's second hottest high of the date with 1978) and a low of 60. In 1986 the high was 77 with a low of 52. The other warm highs were 74 degrees in 1977, 73 degrees in 1975 and 72 degrees in 1994. The record high of 87 degrees was set in 1953 at Midway
. The other warm low of 55 degrees occurred in 2009. 26 of the past 33 highs (79%) were in the: 50s (16) and 60s (10). There were three long periods of 50s and 60s highs. The first was six years from 1980 through 1985. The second was six years from 1988 through 1993. The third was nine years from 1998 through 2006. Four highs (12%) were in the warm: 70s (2) and 80s (2). Three highs (9%) were in the cold 40s. The other warm days were in: 1971 (high of 73, low of 66 (O'Hare's second warmest low of the date)), 1978 (high of 80 (O'Hare's second hottest high of the date with 2007), low of 53) and 1963 (high of 69, low of 59).

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was 80 with a low of 53, a warm day. In 1977 the high was a warm 74 degrees. In 1976 the high was a cold 46 with a low of 30, a cold day. In 1975 the high was a warm 73 degrees. In 1974 the low was a cold 27 degrees. In 1973 the high was 67 with a low of 37, a 30 degree spread. In 1971 the high was 73 with a low of 66, a seven degree spread and warm day. In 1968 the high was 69 with a low of 38, a 31 degree spread. In 1963 the high was 69 with a warm low of 59, a warm day. In 1961 the high was 49 with a low of 44, a five degree spread. In 1960 the high was 49 with a cold low of 27, a cold day. 


More recently, there were large spreads of 32 degrees in 1991 (67/35), 32 degrees in 1999 (68/36) and 31 degrees in 1994 (72/41). There was a small spread of five degrees in 1983 (56/51). 

On the cool side, in 1987 (O'Hare's coolest October 21st) the high was 42 (O'Hare's coolest high of the date) with a low of 32. In 1995 the high was 43 (O'Hare's second coolest high of the date) with a low of 36, a seven degree spread. In 1982 the high was 52 with a low of 27. The record low of 26 degrees was set in 1952 at Midway. The record coolest high of 39 degrees occurred back in 1913, a time when the official readings were taken adjacent to Lake Michigan. 26 of the last 33 lows (79%) were in the: 30s (15) and 40s (11). There were 14 consecutive 30s and 40s lows from 1987 through 2000. One low (3%) was in the cold 20s. Six lows (18%) were in the warm: 50s (4), 60s (1) and 70s (1). 1960 and 1976 share O'Hare's second coolest October 21st days. In 1960 the high was 49 with a low of 27. In 1976 the high was 46 with the second coldest low of 30. O'Hare's coldest lows of the date were 27 degrees in 1960, 1974 and 1982.

There's an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1986 the high was 77 with a low of 52, overall 13.5 degrees ABOVE normal. Then in 1987 the high was 42 with a low of 32, overall 14 degrees BELOW normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:45 and sunrise is at 7:14. Sunset is at 18:01 and twilight ends at 18:30. There's a total of 10 hours, 47 minutes of daylight today and 11 hours, 45 minutes between twilights. We lost four minutes of daylight from yesterday. Tomorrow twilight begins at 6:46 and sunrise is at 7:15. The moon reaches first quarter today at 22:32. Illumination was 40% at midnight, will be 46% at noon and 51% at midnight tonight. Moonrise is at 13:36 this afternoon. Moonset is at 23:54 tonight. Moonrise is at 14:14 tomorrow afternoon. Moonlight time is 10 hours, 18 minutes which is 24 minutes longer than yesterday. 

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is in three days. Halloween is in ten days. Election Day is in 16 days. Standard Time doesn't return until November 4th.  

Saturday, October 20, 2012

October 20: ORD

Today is October 20th. It's the 294th day of the year. 72 days remain. It's week 42 of the year. 
 

Unless noted, the following data is based upon observations collected by the National Weather Service, Chicago, at O'Hare International Airport (ORD) between November 1978 and last year. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before this, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire. 
 
According to the National Climatic Data Center (NCDC), the normal high is 61 and the normal low is 42. I've calculated the 33-year averages at 60 and 42.


On the warm side, in 1979 (O'Hare's warmest October 20th) the high was 80 with a low of 68 (O'Hare's warmest low of the date). The record warmest low of 68 degrees also occurred in 1979 at Midway. This was also the only 60s low in O'Hare's history on October 20th. In 2000 the high was 77 with a low of 55. Three years later, in 2003, the high was 85 (O'Hare's hottest high of the date) with a low of 46, a 39 degree spread. The other warm highs were 74 degrees in 1986, 73 degrees in 1978 and 73 degrees in 2007. The record high of 86 degrees was set in 1953 at Midway
. 18 of the past 33 highs (55%) were in the 50s. 12 highs (36%) were in the warm: 60s (5), 70s (5) and 80s (2). Three highs (9%) were in the cold 40s. O'Hare's second warmest October 20th was in 1971 as the high was 81 (O'Hare's second warmest high of the date) and low of 59 (O'Hare's co-second warmest low of the date). The other warm day was in 1965 as the high was 68 with a low of 59 (the other co-second warmest low of the date).  

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was a warm 73 with a low of 35, a 38 degree spread. In 1976 the high was a cold 47 degrees. In 1975 the high was 72 with a low of 40, a 32 degree spread. In 1974 the high was 47 with a low of 30, a cold day. In 1972 the high was 49 with a low of 25, a cold day. In 1971 the high was 81 with a low of 59, a warm day. In 1970 the high was 55 with a low of 51, a four degree spread. In 1966 the high was 63 with a low of 32, a 31 degree spread. In 1965 the high was 68 with a warm low of 59, a warm day. In 1964 the high was 45 with a low of 23, a cold day. That low of 23 was colder than the record low. In 1961 the high was a cold 48 with a low of 45, a three degree spread. In 1960 the high was 45 with a low of 29, a cold day.
Tom Skilling reported on his blog that back in 1952, three inches of lake-effect snow fell in Chicago but melted quickly. The high that day was just 41 with a low of 29.

More recently, there was an additional large spread of 35 degrees in 1986 (74/39). There were additional small spreads of three degrees in 2004 (53/50), four degrees in 1983 (52/48), four degrees last year, in 2011 (47/43) and six degrees in 1985 (57/51).

On the cool side, in 1989 (O'Hare's third coolest October 20th) the high was 41 (O'Hare's coolest high of the date) with a low of 34. In 2002 the high was 52 with a low of 29. The other cool highs were 47 degrees in 1976, 47 degrees last year (in 2011), 48 degrees in 1961 and 49 degrees in 1995. The other cold low of 29 degrees occurred in 1991. The record low of 24 degrees was last set in 1930 but originally set way back in 1895. The record coolest high of 36 degrees occurred way back in 1895. As you can see, 1895 was by far the coldest of all October 20ths. The official readings were taken adjacent to Lake Michigan in 1895 and at the University of Chicago in 1930. 27 of the last 33 lows (82%) were in the: 30s (11) and 40s (16). Two lows were in the cold 20s. Four lows were in the warm: 50s (3) and 60s (1). O'Hare's coolest October 20th was in 1964 as the high was 45 (O'Hare's co-second coolest high of the date) and low of 23 (O'Hare's coldest low of the date and a low colder than the record low). There's a tie for O'Hare's second coolest October 20ths between 1960 and 1972. In 1960 the high was 45 (O'Hare's other co-second coolest high of the date) and low of 29. In 1972 the high was 49 with a low of 25 (O'Hare's second coldest low of the date). The other cool day was in 1974 as the high was 47 with a low of 30.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:44 and sunrise is at 7:12. Sunset is at 18:03 and twilight ends at 18:31. There's a total of 10 hours, 51 minutes of daylight today and 11 hours, 47 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 6:45 and sunrise is at 7:14. The moon is waxing crescent. Illumination was 29% at midnight, will be 35% at noon and 40% at midnight tonight. Moonrise is at 12:52 this afternoon. Moonset is at 22:46 tonight. Moonrise is at 13:36 tomorrow afternoon. Moonlight time is 9 hours, 54 minutes which is 13 minutes longer than yesterday.

Warm Fall began September 22nd and runs for 41 days through November 1st. High temperatures in this period are usually in the 50s, 60s and 70s. Highs in the 30s and 40s occur infrequently. United Nations Day is in four days. Halloween is in 11 days. Election Day is in 17 days. Standard Time doesn't return until November 4th.