March 3: ORD

Today is March 3rd. It's the 63rd day of the year. 303 days remain. It's week 9 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 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 41 and the normal low is 25. I've calculated the 33-year averages at 38 and 22.

On the warm side, in 1983 the high was 73 with a low of 37, a 36 degree spread. In 2004 the high was 47 with a low of 38 (our most recent 30s low). Another warm high was 56 in 2008. The record high of 80 was set in 1974 at Midway. The record warmest low of 48 occurred way back in 1880, at a time when the official readings were taken adjacent to Lake Michigan. 27 of the past 33 highs (82%) were in the: 30s (17) and 40s (10). O'Hare recorded 12 consecutive highs in the 30s & 40s from 1984 through 1995. On the warm side, two highs were in the: 50s (1) and 70s (1). O'Hare's warmest day was in 1974 when the high was 76 (O'Hare's warmest high) with a low of 42. The other pre-1979 warm highs were 58 in 1966, 57 in 1961 and 55 in both 1970 and 1973. Remarkably, there have been no highs in the 60s at O'Hare on this date ever. On the cold side, four highs were in the 20s.

In looking back through the years to the first March at O'Hare in 1959, the following instances were notable: In 1978 the high was a cold 22 with a low of 14, a cold day. In 1977 the high was 46 with a warm low of 39, a seven degree spread. In 1974 the high was 76 with a low of 42, a 34 degree spread, a warm day and also the day of the record high of 80 at Midway. In 1973 the high was 55 with a low of 46, a warm day. In 1971 the high was a cold 29 degrees. In 1970 the high was 55 with a low of 40, a warm day. In 1968 the high was 46 with a cold low of 10, a 36 degree spread. In 1966 the high was 58 with a low of 44, a warm day. In 1964 the low was a warm 38 degrees. In 1961 the high was a warm 57 degrees. In 1960 the high was 23 with a low of 8, a cold day.

More recently, we had small spreads of four degrees in 1992 (40/36), seven degrees on three days: 1985 (36/29), 1998 (37/30) and 2007 (27/20). There was one large spread of 32 degrees three years ago in 2008 (56/24).

On the cold side, in 2002 (O'Hare's coldest March 3rd) the high was 21 with a low of 0. In 1996 the high was 25 with a low of 1. In 2003 the high was 31 with a low of 8 (our most recent single digit low). In 1980 the high was 35 with a low of 8. The other cold low was 12 in 1995. The other cold highs were 27 in both 1982 and 2007. The record low of -6 and the record coldest high of 8 were set on the same cold day way back in 1873, at a time when the official readings were taken adjacent to Lake Michigan. 16 of the last 33 lows (49%) were in the 20s. O'Hare recorded seven consecutive lows in the 20s from 1985 through 1991. 11 lows (33%) were in the cold: single digits (4) and 10s (a.k.a. teens) (7). O'Hare's only pre-1979 single digit low was 8 in 1960. Six lows (18%) were in the warm 30s. O'Hare's warmest lows were in the 40s and all before 1979. The warmest was 46 in 1973, then 44 in 1966 and 40 in 1970.

Today is a major day in Chicago's snow history. In 2002, 0.8 inches fell. This was the third of four days in which a total of 10.2 inches fell. This comprised 91% of the month's total of 11.2 inches. In 1982, 0.1 inches fell. This was the second of three days in which 12.1 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:57 and sunrise is at 6:25. Sunset is at 17:46 and twilight ends at 18:14. There's a total of 11 hours, 21 minutes of daylight today and 12 hours, 17 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 5:55 and sunrise is at 6:23. The moon is waxing gibbous. Illumination was 71% at midnight, will be 75% at noon and 80% at midnight tonight. Moonset is at 3:06 this morning. Moonrise is at 12:52 this afternoon. Moonset is at 3:47 tomorrow morning. Moonlight time is 14 hours, 14 minutes which is 15 minutes shorter 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 14 days.