January 24: ORD

Today is January 24th. It's the 24th day of the year. 342 days remain. It's week 4 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. Observations have been official at O'Hare 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. 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 31 and the normal low is 16. I've calculated the 33-year averages at 29 and 17.

On the warm side, in 1981 the high was 53 (O'Hare's only 50s high of the date) with a low of 28. In 1990 the high was 45 with a low of 33. Two years ago, in 2010, the high was 46 with a low of 30. In 1989 the high was 43 with a low of 32. In 2002 the high was 40 with a low of 32. The other warm lows were 32 in 1994, 31 in 1983, 31 in 1999, 30 in 1984 and 29 in 2006. The record high of 65 and record warmest low of 44 were set on the same warm day in 1967 at Midway. This was the pre-blizzard period of 1967. 20 of the past 33 highs (61%) were in the: 20s (8) and 30s (12). There were eight consecutive 20s & 30s highs from 1992 through 1999. O'Hare's most recent 30s high is 31 in 2005. On the warm side, six highs (18%) were in the: 40s (5) and 50s (1). O'Hare's warmest highs of the date are 61 in 1967 and 60 in 1964. On the cold side, seven highs (21%) were in the: single digits (2) and 10s (a.k.a. teens) (5). Before 1982, O'Hare's coldest high was 4 in 1963.

In looking back through the years to the first January at O'Hare in 1959, the following instances were notable: In 1977 the high was 30 with a low of 27, a three degree spread. In 1976 the high was 34 with a low of 27, a seven degree spread. in 1975 the high was 43 with a low of 31, a warm day. In 1974 the high was 43 with a low of 29, a warm day. In 1972 the high was a warm 43 with a low of 9, a 34 degree spread. In 1969 the high was a cold 19 with a low of 5, a cold day. In 1967 the high was 61 with a low of 39, a warm day, year of the record high of 65 (at Midway) and record warmest low of 44 (at Midway), a pre-blizzard warm day. In 1966 the high was 11 with a low of -11, a cold day. In 1964 the high was a warm 60 with a low of 25, a 35 degree spread and warm day. In 1963 the high was 4 with a low of -12, a cold day. In 1961 the high was 11 with a low of -2, a cold day. In 1959 the high was 38 with a low of 6, a 32 degree spread.

More recently, we had small spreads of two degrees in 1983 (33/31), four degrees in 1999 (35/31), five degrees in 1985 (27/22), five degrees in 1994 (37/32), six degrees in 2007 (28/22) and seven degrees in 1998 (31/24).

On the cold side, in 1982 the high was 3 (O'Hare's coldest high of the date) with a low of -3, a six degree spread. Five years later, in 1987, the high was 9 with a low of -5. In 2008 the high was 10 with a low of -4. Three years ago, in 2009, the high was 13 with a low of -1. In 2000 the high was 15 with a low of -3. In 1991 the high was 14 with a low of 2. In 2003 the high was 16 with a low of 2. The record low of -15 was set way back in 1897. The record coldest high of -2 occurred way back in 1904. Both records were set at a time when the official readings were taken adjacent to Lake Michigan. 17 of the last 33 lows (52%) were in the: 20s (9) and 30s (8). O'Hare's warmest low of the date is 39 in 1967. 16 lows (48%) were in the cold: negative single digits (5), single digits (5) and 10s (a.k.a. teens) (6). O'Hare's most recent single digit low is 8 in 2004. O'Hare's coldest lows of the date are -12 in 1963 and -11 in 1966.

There were four instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1981 the high was 53 with a low of 28, overall 16.5 degrees ABOVE normal. Then in 1982 the high was 3 with a low of -3, overall 24 degrees BELOW normal. In the second instance, in 1990 the high was 45 with a low of 33, overall 15 degrees ABOVE normal. Then in 1991 the high was 14 with a low of 2, overall 16 degrees BELOW normal. In the third instance, in 2002 the high was 40 with a low of 32, overall 12 degrees ABOVE normal. Then in 2003 the high was 16 with a low of 2, overall 15 degrees BELOW normal. In the fourth instance, in 2009 the high was 13 with a low of -1, overall 18 degrees BELOW normal. Then in 2010 the high was 46 with a low of 30, overall 14 degrees ABOVE normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:44 and sunrise is at 7:14. Sunset is at 16:57 and twilight ends at 17:27. There's a total of 9 hours, 43 minutes of daylight today and 10 hours, 43 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 6:43 and sunrise is at 7:13. The moon is waxing crescent, having passed new yesterday at 1:39. Illumination was 1% at midnight, will be 3% at noon and 4% at midnight tonight. Moonrise is at 7:41 this morning. Moonset is at 18:51 tonight. Moonrise is at 8:09 tomorrow morning. Moonlight time is 11 hours, 10 minutes which is 34 minutes longer than yesterday.

Winter began December 1st and runs for 102 days through March 11th. High temperatures in this period are usually in the 20s and 30s. Highs in the 40s and 50s occur infrequently. National Freedom Day is in eight days. Groundhog Day is in nine days.