March 23: ORD

Today is March 23rd. It's the 82nd day of the year. 283 days remain. It's week 12 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 49 and the normal low is 31. I've calculated the 32-year averages at 52 and 31.

On the warm side, in 1994 the high was 74 with a low of 49. Six years earlier, in 1988, the high was 68 with a low of 45. in 1979 the high was 62 with a low of 50. The record warmest low of 50 occurred in 1936. Since O'Hare was not the official station of record in 1979, this low of 50 is not the record. In 1987 the high was 67 with a low of 40. In 2003 the high was 63 with a low of 41. Another warm high was 62 in 2000. Another warm low was 44 in 2007. The record high of 80 was set way back in 1907. 28 of the last 32 highs (88%) were in the: 40s (9), 50s (11) and 60s (8). On the warmer side, one high was in the 70s. On the cold side, three highs were in the 30s.

In looking back through the years to the first March at O'Hare in 1959, the following instances were notable: In 1976 the high was a warm 61 degrees. In 1974 the high was 25 with a low of 12, a cold day. In 1972 the high was a cold 36 degrees. In 1971 the high was a cold 31 with a low of 20, a cold day. In 1969 the high was 66 with a low of 43, a warm day. In 1966 the high was 60 with a low of 27, a 33 degree spread. In 1965 the high was 28 with a low of 8, the coldest March 23 day ever at O'Hare. In 1963 the high was a warm 72 with a low of 30, a 42 degree spread. In 1961 the high was 43 with a low of 36, a seven degree spread. In 1960 the high was 30 with a low of 15, cold day. In 1959 the high was a warm 65 with a low of 32, a 33 degree spread.

More recently, we had small spreads of six degrees in 1985 (44/38) and six degrees in 1993 (42/36). There were large spreads of 37 degrees in 1981 (60/23), 31 degrees in 1999 (53/22) and 31 degrees last year in 2010 (59/28).

On the cold side, in 1983 the high was 32 with a low of 13. In 1990 the high was 38 with a low of 23. Another cold low was 17 in 1992. The record low of 9 and record coldest high of 21 were set on the same cold day back in 1940. 24 of the last 32 lows (75%) were in the: 20s (13) and 30s (11). Two lows were in the cold 10s (a.k.a. teens). Six lows were in the warmer: 40s (5) and 50s (1).

Today is a major day in Chicago's snow history. At O'Hare in 1965, this was the fourth of seven days in which a total of 10.2 inches fell. Today 4.9 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:24 and sunrise is at 6:52. Sunset is at 19:09 and twilight ends at 19:37. There's a total of 12 hours, 17 minutes of daylight today and 13 hours, 13 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:22 and sunrise is at 6:50. The moon is waning gibbous. Illumination was 83% at midnight, will be 78% at noon and 73% at midnight tonight. Moonset is at 8:56 this morning. Moonrise is at 0:31 tomorrow morning. Moonset is at 9:47 tomorrow morning. Moonlight time is 8 hours, 56 minutes which is five minutes longer than yesterday.

April Fool's Day is nine days. The warm part of Spring (Warm Spring) begins in 21 days on April 13. Warm Spring runs for 52 days, through June 3. High temperatures in this period are usually in the 50s, 60s and 70s. Warmer 80s and 90s occur infrequently. -Bernie-