Friday, April 3, 2009

April 3: ORD

Today is April 3rd. It's the 93rd day of the year. 272 days remain. It's week 14 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 53 and the normal low is 34. I've calculated the 30-year averages at 56 and 36.


On the warm side, in 1981 the high was 75 with a low of 59. In 1999 the high was 73 with a low of 52. Two years earlier, in 1997, the high was 67 with a low of 52. Other warm highs were 70 in 1996, 70 two years ago and 65 in 1991. The record high of 81 was set in 1956 and the record warmest low of 60 was set back in 1928.
26 of the last 30 highs were: 40s (9), 50s (8) and 60s (9). On the warmer side, four highs were 70s.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1978 the high was 70 with a low of 37, a 33 degree spread and bonus 70s day. In 1976 the high was 72 with a low of 45, a bonus 70s day. In 1975 the high was 31 with a low of 19, a cold day. In 1974 the high was 65 with a low of 50, a bonus 60s day. In 1973 the high was 44 with a low of 38, a six degree spread. In 1963 the high was 70 with a low of 39, a 31 degree spread and bonus 70s day.

More recently, we had a small spread of three degrees in 1983 (40/37). There were large spreads of 32 degrees in 2004 (59/27), 33 degrees in 2005 (64/31), 35 degrees two years ago (70/35), 37 degrees in 1982 (62/25) and 38 degrees in 1996 (70/32).

On the cold side, in 1987 the high was 40 with the record low of 17. Another cold low was 22 in 1993. Other cold highs were 40 in 1983 and 40 in 2002. The record coldest high of 25 was set in 1954. 15 of the last 30 lows were 30s. Six lows were in the colder: 10s (a.k.a. teens)(1) and 20s (5). Nine lows were in the warmer: 40s (6) and 50s (3).

Today is a major day in Chicago's snow history. At O'Hare and Midway in 1975, this was the second day of a two day storm. At O'Hare, 0.4 inches of an 11.1 inch total occurred. At Midway, 0.4 inches of a 9.8 inch total occurred.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:04 and sunrise is at 6:32. Sunset is at 19:22 and twilight ends at 19:50. Tomorrow twilight begins at 6:02 and sunrise is at 6:30. There's a total of 12 hours, 50 minutes of daylight today and 13 hours, 46 minutes between twilights. The moon is waxing gibbous and reached first quarter yesterday at 9:34. Illumination was 57% at midnight, will be 63% at noon and 68% at midnight tonight. Moonset was at 3:16. Moonrise is at 12:49 today and moonset is at 3:52 tomorrow. Moonlight time is 14 hours, 27 minutes which is 30 minutes shorter than yesterday.

Palm Sunday is in two days. Good Friday is in seven days. Steve, one of my brother-in-laws, celebrates a birthday in eight days. Easter is in nine days. One of my nieces, Sara, celebrates a birthday in 13 days. -Bernie-

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