November 2: ORD

Today is November 2nd. It's the 307th day of the year. 59 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 55 and the normal low is 38. I've calculated the 34-year averages at 54 and 37.

On the warm side, in 1990 (O'Hare's second warmest November 2nd) the high was 73 with a low of 58. Three years earlier, in 1987, the high was 71 with a low of 58. Those lows of 58 degrees are O'Hare's warmest lows of the date. The other warm highs were 70 degrees in 1978, 68 degrees in 1965, 68 degrees in 1971 and 67 degrees in 2008. The other warm lows were 53 degrees in 1983 and 50 degrees in 1981. The record high of 78 degrees was set in 1974 at Midway. The record warmest low of 62 degrees occurred in 1944 at Midway. 27 of the past 34 highs (79%) were in the: 40s (8), 50s (10) and 60s (9). O'Hare recorded nine consecutive highs in the 40s, 50s and 60s from 1997 through 2005. Our most recent 40s high was 49 degrees in 2004. Four highs (12%) were in the cold 30s. Three highs (9%) were in the warm 70s. O'Hare's warmest November 2nd was in 1961 as the high was 77 (O'Hare's hottest high of the date) and low of 56. The other warm 11/2 days are: 1975 (high of 73, low of 56), 1977 (high of 73, low of 56), 1974 (high of 74 (O'Hare's second hottest high of the date), low of 49)) and 1964 (high of 66, low of 51). Those lows of 56 degrees (1961, 1975 and 1977) are O'Hare's second warmest lows of the date.   

In looking back through the years to the first November at O'Hare in 1958, the following instances were notable: in 1977 the high was 73 with a low of 56, a warm day. In 1975 the high was 73 with a low of 56, a warm day. In 1974 the high was 74 with a low of 49, a warm day and year of the record high of 78 at Midway. In 1971 the high was a warm 68 degrees. In 1970 the high was 44 with a low of 40, a four degree spread. In 1969 the high was 47 with a low of 44, a three degree spread. In 1967 the high was 48 with a low of 41, a seven degree spread. In 1966 the high was a cold 39 with a low of 27, a cold day. In 1965 the high was a warm 68 with a low of 38, a 30 degree spread. In 1964 the high was 66 with a warm low of 51, a warm day. In 1963 the high was 47 with a cold low of 22 degrees, a cool day. In 1962 the low was a cold 24 degrees. In 1961 the high was 77 with a low of 56, a warm day. In 1960 the high was a cold 42 with a low of 38, a four degree spread.

More recently, there were large spreads of 31 degrees in 1978 (70/39) and 31 degrees in 1995 (60/29). There were small spreads of four degrees in 2004 (49/45) and seven degrees in 2003 (55/48).

On the cool side, in 1991 (O'Hare's coolest November 2nd) the high was 32 (O'Hare's coolest high of the date) with a low of 18 (O'Hare's coldest and only 10s (a.k.a. teens) low of the date). In 1984 (O'Hare's second coolest November 2nd) the high was 36 with a low of 21 (O'Hare's second coldest low of the date). In 2006 the high was 34 (O'Hare's second coolest high of the date) with a low of 24. A decade earlier, in 1996, the high was 37 with a low of 22. In 1989 the high was 41 with a low of 26. The other cold lows were 24 degrees in 1962 and 25 degrees in 1980. The other cool high of 42 degrees occurred in 1960. The record low of 14 degrees and record coolest high of 29 degrees were set on the same cold day in 1951 at Midway. 29 of the last 34 lows (85%) were in the: 20s (8), 30s (13) and 40s (8). One low was in the cold 10s (a.k.a. teens). Four lows were in the warm 50s. All four of the post-1978 50s lows occurred in a decade long span from 1981 through 1990. O'Hare's other cool days are: 1966 (high of 39, low of 27) and 1963 (high of 47, low of 22).

There's an instance of back-to-back-to-back years in which temperatures were just about as opposite as they can be. In 1989 the high was 41 with a low of 26, overall 13.5 degrees BELOW normal. Then in 1990 the high was 73 with a low of 58, overall 18.5 degrees ABOVE normal. Then in 1991 the high was 32 with a low of 18, overall 22 degrees BELOW normal. 

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:59 and sunrise is at 7:28. Sunset is at 17:45 and twilight ends at 18:14. There's a total of 10 hours, 17 minutes of daylight today and 11 hours, 15 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 7:00 and sunrise is at 7:30. The moon is waning gibbous. Illumination was 90% at midnight, will be 87% at noon and 84% at midnight tonight. Moonset was at 10:51 this morning. Moonrise is at 20:30 tonight. Moonset is at 11:36 tomorrow morning. Moonlight time is 14 hours, 21 minutes which is the same as yesterday. Moonlight time is at its peak today, as it was yesterday.

Cool Fall begins today, November 2nd and runs for 29 days through November 30th. High temperatures in this period are usually in the 30s, 40s and 50s. Highs in the 10s and 20s occur infrequently. Standard Time returns in two days. Election Day is in four days.