March 15: ORD

Today is March 15th. It's the 74th day of the year. 291 days remain. It's week 11 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 46 and the normal low is 28. I've calculated the 32-year averages at 46 and 28.

On the warm side, in 1995 the high was the record high of 74 with a low of 43, a 31 degree spread. Five years earlier, in 1990, the high was 68 with a low of 45. In 2000 the high was 65 with a low of 34, a 31 degree spread. Other warm highs were 62 in 1981, 59 in 2002 and 58 two years ago in 2009. The record warmest low of 49 occurred back in 1945. 13 of the last 32 highs (41%) were in the 40s. On the warmer side, ten highs (31%) were in the: 50s (6), 60s (3) and 70s (1). On the cold side, nine highs (28%) were in the: 20s (2) and 30s (7).

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 36 with a low of 31, a five degree spread. In 1977 the high was 71 with a low of 44, a warm day. In 1973 the high was 57 with a warm low of 41, a warm day. In 1971 the high was a warm 58 degrees. In 1970 the high was 33 with a low of 16, a cold day. In 1968 the high was a warm 60 with a low of 39, a warm day. In 1967 the high was a cold 34 degrees. In 1962 the high was a cold 28 with a low of 21, a seven degree spread and cold day. In 1960 the high was a cold 33 degrees.

More recently, we had small spreads of six degrees in 1987 (38/32), seven degrees in 1982 (43/36) and seven degrees in 1986 (41/34). Other large spreads were 34 degrees in 1993 (47/13), 32 degrees in 1981 (62/30) and 30 degrees two years ago in 2009 (58/28).

On the cold side, in 1997 the high was 26 with a low of 13. In 1979 the high was 25 with a low of 15. In 1988 the high was 30 with a low of 17. Another cold low was 13 in 1993. Another cold high was 32 in 1998. The record low of 6 was last set way back in 1890 but originally occurred in 1877. The record coldest high of 17 was occurred back in 1893. 26 of the last 32 lows (81%) were in the: 20s (16) and 30s (10). Four lows were on the cold 10s (a.k.a. teens). On the warmer side, two lows were in the 40s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:38 and sunrise is at 7:06. Sunset is at 19:00 and twilight ends at 19:28. There's a total of 11 hours, 54 minutes of daylight today and 12 hours, 50 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:36 and sunrise is at 7:04. The moon is waxing gibbous. Illumination was 73% at midnight, will be 78% at noon and 83% at midnight tonight. Moonset is at 4:17 this morning. Moonrise is at 14:21 this afternoon. Moonset is at 4:54 tomorrow morning. Moonlight time is 13 hours, 56 minutes which is 29 minutes shorter than yesterday.

St. Patrick's Day is in two days. The warm part of Spring (Warm Spring) begins in 29 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-