March 19: ORD

Today is March 19th. It's the 78th day of the year. 287 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 47 and the normal low is 29. I've calculated the 32-year averages at 47 and 30.

On the warm side, in 1979 the high was 63 with a low of 55. Last year, in 2010, the high was 65 with a low of 39. In 1985 the high was 63 with a low of 37. A decade later, in 1995, the high was 55 with a low of 45. Another warm high was 61 in 2007. The record high of 78 was set back in 1921. The record warmest low of 59 occurred way back in 1903. 28 of the last 32 highs (88%) were in the: 30s (9), 40s (11) and 50s (8). Our most recent 30s high was 39 in 1998. On the warmer side, four highs were in the 60s.

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 76 with a low of 51, a warm day. Also in 1976, the temperature fell to 25 degrees on the 21st, a huge 51 degree drop! In 1969 the high was a warm 61 degrees. In 1968 the high was 62 with a low of 44, a warm day. In 1965 the high was 19 with a low of 7, a cold day. In 1959 the high was a warm 65 with a low of 40, a warm day.

More recently, we had small spreads of three degrees in 1983 (35/32), four degrees in 1982 (39/35), five degrees in 1984 (33/28), five degrees in 1998 (39/34), six degrees in 1996 (38/32) and six degrees in 2000 (42/36). There was a large spread of 35 degrees in 1986 as the high was 53 with a low of 18.

On the cold side, in 1990 the high was 31 with a low of 21. A year before, in 1989, the high was 37 with a low of 15. In 1981 the high was 32 with a low of 20. Other cold highs were 33 in 1984, 33 in 1993 and 35 in 1983. The record low of 0 and record coldest high of 17 were set on the same cold day back in 1923. 28 of the last 32 lows (88%) were in the: 20s (13) and 30s (15). Two lows were in the cold 10s (a.k.a. teens). Two lows were in the warmer: 40s (1) and 50s (1).

Today is a major day in Chicago's snow history. In 1983 at O'Hare, this was the first day of a three day storm which produced 7.2 inches. Today 0.9 inches fell.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:31 and sunrise is at 6:59. Sunset is at 19:04 and twilight ends at 19:32. There's a total of 12 hours, 5 minutes of daylight today and 13 hours, 1 minute between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:29 and sunrise is at 6:57. The moon is waxing gibbous and is full today at 13:10. It's the full Worm or Sap moon. Illumination was 99% at midnight, will be 100% at noon and 99% at midnight tonight. Moonset is at 6:29 this morning. Moonrise is at 19:29 tonight. Moonset is at 7:00 tomorrow morning. Moonlight time is 11 hours which is 49 minutes shorter than yesterday. The Spring Equinox is tomorrow at 18:21.

April Fool's Day is 13 days. The warm part of Spring (Warm Spring) begins in 25 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-