Thursday, October 29, 2009

October 25: ORD

Today is October 25th. It's the 298th day of the year. 67 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 58 and the normal low is 38. I've calculated the 30-year averages at 57 and 38.


On the warm side, in 1989 the high was 77 with a low of 52. In 2000 the high was 69 with a low of 55. Other warm highs were 75 in 2004 and 70 in 1993. Another warm low was 52 in 1986. The record high of 79 and record warmest low of 62 were set in on the same day in 1963
. Over the last 30 years, 26 highs have been: 40s (7), 50s (10) and 60s (9). Three highs were in the warmer 70s and one high was in the cooler 30s.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1977 the low was a warm 51 degrees. In 1971 the high was 69 with a low of 59, a warm day. In 1970 the low was a warm 51 degrees. In 1967 the high was 44 with a low of 38, a six degree spread. In 1966 the high was 57 with a cold low of 26, a 31 degree spread. In 1964 the high was a warm 76 with a low of 41, a 35 degree spread. In 1963 the high was 77 with a low of 51, a warm day and year of the record high and record warmest low. In 1962 the high was 38 with a low of 21, a cool day. In 1959 the high was a cool 40 with a low of 35, a five degree spread.


More recently, there was a
large spread of 37 degrees in 2004 (75/38), 31 degrees in 1985 (67/36), 30 degrees in 1996 (68/38) and 30 degrees in 1999 (65/35). There were small spreads of three degrees in 1986 (55/52), four degrees in 1997 (49/45), five degrees in 1994 (46/41), five degrees in 2001 (40/35) and five degrees in 2002 (47/42).

On the cool side, in 1988 the high was 43 with a low of 26. In 1980 the high was 39 with a low of 33. Another cool low was 26 in 1982. Other cool highs were 40 in 2001, 45 in 1981, 46 in 1979 and 46 in 1994. 23 of the last 30 lows were: 30s (14) and 40s (9). Four lows were in the cooler 20s. Three lows were in the warmer 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:49 and sunrise is at 7:18. Sunset is at 17:56 and twilight ends at 18:25. Tomorrow twilight begins at 6:51 and sunrise is at 7:19. There's a total of 10 hours, 38 minutes of daylight today (two minutes less than yesterday) and 11 hours, 36 minutes between twilights. The moon is waxing crescent and reaches first quarter tonight at 19:42. Illumination was 43% at midnight, will be 48% at noon and 52% at midnight tonight. Moonrise is at 14:01. Moonset is at 23:52. Moonlight time is 9 hours, 51 minutes which is 30 minutes longer than yesterday.

A sister, Mary Ann, celebrates a birthday tomorrow. Halloween is in six days. -Bernie-

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