Friday, October 30, 2009

October 30: ORD

Today is October 30th. It's the 303rd day of the year. 62 days remain. It's week 44 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 55 and the normal low is 37. I've calculated the 30-year averages at 61 and 40.


On the warm side, in 1999 the high was 76 with a low of 56. A decade earlier, in 1989, the high was 75 with a low of 55. In 2004 the high was 72 with a low of 50. In 1990 the high was 73 with a low of 48. In 1998 the high was 65 with a low of 56. In 1981 the high was 75 with a low of 45, a 30 degree spread. The next year, 1982, the high was 67 with a low of 50. Other warm highs were 72 in 1987, 70 in 2003, 70 in 2006 and 67 in 1979. The record high of 85 was set in 1950. The record warmest low of 62 occurred in 1974.
Over the last 30 years, there have been four categories of highs and they've been fairly well distributed. Right in the middle are the 60s with ten. On the warmer side, there's been eight highs in the 70s. On the cooler side, seven highs were in the 50s and five were only in the 40s.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was a warm 69 degrees. In 1976 the high was 49 with a low of 42, a seven degree spread. In 1974 the high was 76 with a low of 62, a warm day. 1974 was also the year of the record warmest low. In 1971 the high was 80 with a low of 55, a warm day. In 1967 the low was a warm 49 degrees. In 1966 the high was 52 with a cool low of 22, a 30 degree spread. In 1965 the high was a warm 69 degrees. In 1964 the high was 58 with a low of 24, a 34 degree spread. In 1963 the high was 58 with a low of 27, a 31 degree spread. In 1960 the low was a warm 51 degrees.


More recently, there were
large spreads of 36 degrees in 1987 (72/36) and 30 degrees in 2003 (70/40). There were small spreads of four degrees in 1992 (46/42), five degrees in 1995 (45/40), five degrees in 2001 (52/47) and seven degrees in 2002 (48/41).

On the cool side, in 1988 the high was 45 with the record low of 21. Another cool low was 24 in 1980. Another cool high was 40 in 1993. The record coolest high of 28 occurred back in 1917. 23 of the last 30 lows were: 30s (13) and 40s (10). Two lows were in the cooler 20s. Five lows were in the warmer 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:55 and sunrise is at 7:24. Sunset is at 17:49 and twilight ends at 18:18. Tomorrow twilight begins at 6:56 and sunrise is at 7:25. There's a total of 10 hours, 25 minutes of daylight today (two minutes less than yesterday) and 11 hours, 23 minutes between twilights. The moon is waxing gibbous, heading towards the full Beaver moon in three days. Illumination was 86% at midnight, will be 90% at noon and 93% at midnight tonight. Moonset was at 4:01. Moonrise is at 15:57. Moonset is at 5:06 tomorrow morning. Moonlight time is 12 hours, 4 minutes which is 42 minutes longer than yesterday.

Halloween is tomorrow. Election Day is in four days. -Bernie-

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