Wednesday, October 28, 2009

October 24: ORD

Today is October 24th. It's the 297th day of the year. 68 days remain. It's week 43 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 59 and the normal low is 39. I've calculated the 30-year averages at 57 and 39 (a two degree drop in the average high and average low from yesterday).


On the warm side, in 1991 the high was 74 with the record warmest low of 63. Two years prior, in 1989, the high was 76 with a low of 51. In 2000 the high was 67 with a low of 58. Another warm high was 71 in 1985. Another warm low was 54 in 1986. The record high of 83 was set in 1963
. Over the last 30 years, 27 highs have been: 40s (7), 50s (12) and 60s (8). Three highs were in the warmer 70s.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1976 the high was 49 with a low of 43, a six degree spread. In 1975 the high was 74 with a low of 47, a warm day. In 1974 the high was a warm 71 degrees. In 1973 the high was 78 with a low of 53, a warm day. In 1972 the high was 42 with a low of 40, a two degree spread. In 1971 the high was 64 with a low of 61, a warm day and three degree spread. In 1970 the high was 72 with a low of 53, a warm day. In 1966 the high was 60 with a low of 28, a 32 degree spread. In 1964 the high was 62 with a cold low of 24, a 38 degree spread. In 1963 the high was 82 with a low of 53, a warm day and year of the record high. In 1962 the high was 45 with a low of 25, a cool day. In 1960 the high was 43 with a low of 29, a cool day.


More recently, there was a
large spread of 34 degrees in 1982 (57/23). There were small spreads of four degrees in 1983 (51/47), four degrees in 1986 (58/54), four degrees in 2002 (46/42) and six degrees in 1997 (49/43).

On the cool side, in 1981 the high was the record co-coolest high of 40 with the record low of 17. In 1988 the high was the record co-coolest high of 40 with a low of 26. Another cool low was 23 in 1984. Other cool highs were 45 in 1987, 46 in 2002 and 47 in 2006. 21 of the last 30 lows were: 30s (8) and 40s (13). Five lows were in the cooler: 10s (1) and 20s (4). Four lows were in the warmer: 50s (3) and 60s (1).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:48 and sunrise is at 7:17. Sunset is at 17:57 and twilight ends at 18:26. Tomorrow twilight begins at 6:49 and sunrise is at 7:18. There's a total of 10 hours, 40 minutes of daylight today (three minutes less than yesterday) and 11 hours, 38 minutes between twilights. The moon is waxing crescent, heading towards first quarter tomorrow. Illumination was 34% at midnight, will be 38% at noon and 43% at midnight tonight. Moonrise is at 13:29. Moonset is at 22:50. Moonlight time is 9 hours, 21 minutes which is 21 minutes longer than yesterday.

United Nations Day is today. A sister, Mary Ann, celebrates a birthday in two days. Halloween is in a week. -Bernie-

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