March 7: ORD

Today is March 7th. It's the 66th day of the year. 299 days remain. It's week 10 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.

According to the National Climatic Data Center (NCDC), the normal high is 42 and the normal low is 26. I've calculated the 32-year averages at 40 and 25.

On the warm side, in 2000 the high was the record high of 78 with the record warmest low of 53. In 1987 the high was the former record high of 74 with a low of 45. In 1983 the high was 60 with a low of 44. In 1992 the high was 51 with a low of 44, a seven degree spread. Other warm highs were 57 in both 1988 and 2005. Another warm low was 39 two years ago in 2009. 24 of the last 32 highs (75%) were in the: 20s (6), 30s (9) and 40s (9) . Our most recent 30s high was 35 in 2003. On the warmer side, six highs were in the: 50s (3), 60s (1) and 70s (2). On the cold side, two highs were in the 10s (a.k.a. teens).

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 30 with a low of 25, a five degree spread. In 1975 the high was 38 with a low of 31, a seven degree spread. In 1974 the high was 52 with a warm low of 40, a warm day. In 1973 the high was 62 with a low of 44, a warm day. In 1971 the high was a cold 30 degrees. In 1968 the high was a warm 54 with a low of 19, a 35 degree spread. In 1967 the high was a cold 30 with a low of 15, a cold day. In 1965 the high was 34 with a low of 30, a four degree spread. In 1960 the high was 24 with a low of 3, a cold day.

More recently, we had small spreads of four degrees in 1979 (37/33), five degrees in 2002 (38/33), six degrees two years ago (in 2009) (45/39) and seven degrees in 2007 (28/21). The large spreads were 30 degrees in 1997 (49/19) and 30 degrees in 2005 (57/27).

On the cold side, in 1996 the high was 17 with a low of 5. A decade earlier, in 1986, the high was 18 with a low of 7. Four years before that, in 1982, the high was 20 with a low of 6. Two years later, in 1984, the high was 25 with a low of 11. Three years ago, in 2008, the high was 26 with a low of 14. In 1999 the high was 26 with a low of 15. A decade before that, in 1989, the high was 28 with a low of 17. Another cold high was 28 four years ago in 2007. The record low of -2 and record coldest high of 14 were set on the same cold day in 1943. 13 of the last 32 lows (41%) were in the 20s. Nine lows ( 28%) were in the cold: 10s (a.k.a. teens) (6) and single digits (3). Ten lows (31%) were in the warmer: 30s (6), 40s (3) and 50s (1).

Today is a major day in Chicago's snow history. In 1999, 2.8 inches fell. This was the third of six days in which a total of 18.2 inches fell. Back in 1931 at the University of Chicago, where official stats for Chicago used to be kept, 10.9 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:51 and sunrise is at 6:19. Sunset is at 17:50 and twilight ends at 18:18. There's a total of 11 hours, 31 minutes of daylight today and 12 hours, 27 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 5:50 and sunrise is at 6:18. The moon is waxing crescent. Illumination was 5% at midnight, will be 7% at noon and 10% at midnight tonight. Moonrise is at 7:05 this morning. Moonset is at 20:56 tonight. Moonrise is at 7:32 tomorrow morning. Moonlight time is 13 hours, 51 minutes which is 37 minutes longer than yesterday.

Mardi Gras is tomorrow. Ash Wednesday is in two days. St. Patrick's Day is in ten days. The cool part of Spring (Cool Spring) begins in five days on March 12. Cool Spring runs for 32 days, through April 12. High temperatures in this period are usually in the 30s, 40s and 50s. Warmer 60s and 70s occur infrequently. -Bernie-