February 26: ORD

Today is February 26th. It's the 57th day of the year. 309 days remain. It's week 9 of the year.

Unless noted, the folowing 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 of record 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 39 and the normal low is 24. I've calculated the 33-year averages at 38 and 23.

On the warm side, in 2000 the high was the record high of 64 with the record warmest low of 48. Two years earlier, in 1998, the high was 63 (the former record high which originally occurred in 1932) with a low of 45. Three years ago, in 2009, the high was 53 with a low of 32. The other warm high was 58 in 1988. The other warm low was 38 in 1996. 25 of the past 33 highs (76%) were in the: 30s (18) and 40s (7). There were consecutive highs in the 30s & 40s as follows: seven years from 1981 through 1987 and eight years from 2001 through 2008. On the warm side, four highs (12%) were in the: 50s (2) and 60s (2). O'Hare's pre-1979 warm highs were 61 in 1976 and 56 in 1971. Our most recent 40s high was 42 in 2004. On the cold side, four highs (12%) were in the 20s.

In looking back through the years to the first February at O'Hare in 1959, the following instances were notable: In 1978 the high was 25 with a low of 11, a cold day. In 1976 the high was 61 with a low of 37, a warm day. In 1974 the low was a cold 12 degrees. In 1973 the high was 33 with a low of 28, a five degree spread. In 1972 the low was a cold 9 degrees. In 1971 the high was 56 with a low of 40, a warm day. In 1969 the high was 37 with a low of 30, a seven degree spread. In 1967 the high was 34 with a cold low of -1, a 35 degree spread and cold day. In 1965 the high was 22 with a low of 2, a cold day. In 1964 the low was a cold 10 degrees. In 1963 the high was 15 with a low of -8, a cold day and year of the record low (-1 at Midway). In 1960 the high was a cold 26 with a low of 21, a five degree spread.

More recently, we had small spreads of four degrees in 1997 (38/34), four degrees in 2007 (34/30), five degrees in 1995 (33/28), six degrees in 1981 (36/30) and six degrees in 1996 (44/38). We had a lone large spread of 36 degrees in 1988 (58/22).

On the cold side, in 1994 the high was 20 (our most recent 20s high) with a low of 2. In 1980 the high was 26 with a low of 2. In 2003 the high was 30 with a low of 5. In 1991 the high was 27 with a low of 12. The other cold high was 27 in 1993. The record low of -1 was set in 1963 at Midway. The record low of -1 was originally set way back in 1888. The record coldest high of 10 occurred way back in 1888. In 1888 the official readings were taken adjacent to Lake Michigan. 22 of the last 33 lows (67%) were in the: 10s (a.k.a. teens) (9) and 20s (13). There were six consecutive 10s & 20s lows from 1988 through 1993. Three lows (9%) were in the cold single digits. O'Hare's coldest February 26th was in 1963 when the high was 15 and low was -8. Eight lows (24%) were in the warm: 30s (6) and 40s (2). O'Hare had a pre-1979 warm low of 40 in 1971.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:06 and sunrise is at 6:34. Sunset is at 17:39 and twilight ends at 18:07. There's a total of 11 hours, 5 minutes of daylight today and 12 hours, 1 minute between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:04 and sunrise is at 6:33. The moon is waxing crescent. Illumination was 17% at midnight, will be 21% at noon and 25% at midnight tonight. Moonrise is at 8:23 this morning. Moonset is at 22:44 tonight. Moonrise is at 8:55 tomorrow morning. Moonlight time is 14 hours, 21 minutes which is 31 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. St. Patrick's Day is in 20 days.