Sunday, April 26, 2009

April 24: ORD

Today is April 24th. It's the 114th day of the year. 251 days remain. It's week 17 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 61 and the normal low is 40. I've calculated the 30-year averages at 64 and 42.


On the warm side, in 1990 the high was the record high of 87 with a low of 66. Four years later, in 1994, the high was 83 with a low of 54. In 1986 the high was 81 with a low of 47, a 34 degree spread. In 1993 the high was 76 with a low of 52. Last year the high was 74 with a low of 54. Other warm highs were 75 in 1998, 73 in 1982, 73 in 2002 and 73 three years ago. Two years ago wasn't bad either as the high was 68. The record warmest low of 68 was set in 1915.
25 of the last 30 highs were: 50s (9), 60s (9) and 70s (7). On the warmer side, three highs were in the 80s. On the colder side, two highs were 40s. As a post script, today's high at O'Hare was 84 at 15:13 with a low of 49 at 5:42. This produced a mean of 66.5 which puts the day third warmest of the past 31 years.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1968 the high was 41 with a low of 36, a five degree spread. In 1967 the high was 40 with a low of 25, a cold day. In 1965 the high was 45 with a low of 40, a five degree spread. In 1962 the high was 78 with a low of 44, a 34 degree spread. In 1961 the high was 76 with a low of 40, a 36 degree spread. In 1960 the high was 85 with a low of 65, a warm day.

More recently, we had large spreads of 34 degrees in 2006 (73/39), 32 degrees in 1996 (68/36), 31 degrees in 2002 (73/42) and 30 degrees in 1995 (62/32).

On the cold side, in 1980 the high was 44 with a low of 32. The low was also 32 in 1983. Another cold high was 48 in 1992. The record low of 29 was set back in 1910. The record coldest high of 36 was set way back in 1892. 25 of the last 30 lows were: 30s (14) and 40s (11). Five lows were in the warmer: 50s (4) and 60s (1).

Today is not a major day in Chicago's snow history.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:28 and sunrise is at 5:58. Sunset is at 19:45 and twilight ends at 20:15. Tomorrow twilight begins at 5:27 and sunrise is at 5:57. There's a total of 13 hours, 47 minutes of daylight today and 14 hours, 47 minutes between twilights. The moon is waning crescent and will reach new today at 22:23. Illumination was 1% at midnight, will be 0% at noon and 0% at midnight tonight. Moon rise was at 5:16 and moon set is at 19:44. The moon will rise at 5:47 tomorrow. Moonlight time is 14 hours, 28 minutes which is 48 minutes longer than yesterday.

Arbor Day is today. National Teacher Day is in 11 days. Mother's Day is in 16 days. -Bernie-

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