Monday, April 13, 2009

April 13: ORD

Today is April 13th. It's the 103rd day of the year. 262 days remain. It's week 15 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 57 and the normal low is 37. I've calculated the 30-year averages at 58 and 38.


On the warm side, three years ago the high was 80 with a low of 52. Twenty-five years before that, in 1981, the high was 79 with a low of 50. Four years later, in 1985, the high was 71 with a low of 54. In 1998 the high was 68 with a low of 55. Fifteen years prior, in 1983, the high was 70 with a low of 47. Another warm high was 73 in 1988. The record high of 82 and record warmest low of 62 were set on the same day in 1941.
The record high of 82 also occurred way back in 1887. 12 of the last 30 highs were 50s. On the warmer side, 11 highs were: 60s (6), 70s (4) and 80s (1). On the colder side, seven highs were 40s. Note that all highs have made it out of the 30s.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1977 the high was 77 with a low of 47, a 30 degree spread and bonus 70s day. In 1976 the high was 69 with a low of 32, a 37 degree spread. In 1974 the high was 71 with a low of 48, a warm day. In 1972 the high was 70 with a low of 39, a 41 degree spread. In 1968 the high was 71 with a low of 58, a warm day. In 1967 the high was 72 with a low of 45, another warm day. In 1960 the high was 76 with a low of 53, yet another warm day.

More recently, we had large spreads of 38 degrees in 2003 (67/29) and 41 degrees in 1988 (73/32).

On the cold side, in 1980 the high was 46 with a low of 24. Other cold highs were 42 last year and 43 in 1992. The record low of 21 and record coldest high of 33 were both set on the same day in 1950. 16 of the last 30 lows were 30s. Four lows were in the colder 20s. Ten lows were in the warmer: 40s (6) and 50s (4).

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 5:46 and sunrise is at 6:15. Sunset is at 19:33 and twilight ends at 20:02. Tomorrow twilight begins at 5:45 and sunrise is at 6:14. There's a total of 13 hours, 18 minutes of daylight today and 14 hours, 16 minutes between twilights. The moon is waning gibbous. Illumination was 87% at midnight, will be 83% at noon and 79% at midnight tonight. Moonset is at 8:10. Moonrise is at 0:18 tonight and moonset is at 8:58 tomorrow. Moonlight time is 8 hours, 10 minutes which is 3 minutes longer than yesterday.

One of my nieces, Sara, celebrates a birthday in three days. -Bernie-

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