October 27: ORD

Today is October 27th. It's the 300th day of the year. 65 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 57 and the normal low is 38. I've calculated the 31-year averages at 58 and 40.

On the warm side, in 1984 the high was 76 with the record warmest low of 63. In 1998 the high was 70 with a low of 56. In 1989 the high was 76 with a low of 49. In 2000 the high was 71 (our most recent 70s high) with a low of 51. Other warm lows were 53 in 2004 and 52 in 1996. The record high of 83 was set back in 1927. Over the last 31 years, 26 highs (84%) have been: 40s (7), 50s (9) and 60s (10). Four highs were in the warmer 70s and one high was in the cold 30s. The last 60s high was 62 in 2004.

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 42 with a low of 23, a cold day. In 1974 the high was a warm 72 with a low of 38, a 34 degree spread. In 1971 the high was 74 with a low of 54, a warm day. In 1970 the high was 67 with a warm low of 60, a seven degree spread and warm day. In 1969 the high was a cool 44 with a low of 28, a cool day. In 1967 the high was a cool 41 with a low of 34, a seven degree spread. In 1966 the high was a warm 70 degrees. In 1962 the high was 64 with a low of 34, a 30 degree spread. In 1961 the low was a cold 25 degrees. In 1959 the high was a cool 40 with a low of 33, a seven degree spread.

More recently, there were large spreads of 33 degrees in 1983 (65/32) and 32 degrees in 1982 (65/33). There were small spreads of six degrees last year (51/45), six degrees in 1991 (53/47) and seven degrees in 2006 (45/38).

On the cool side, in 1997 the high was 38 with a low of 26. In 1980 the high was 43 with a low of 27. Other cool highs were 44 in 2003, 45 in 2001 and 45 in 2006. The record low of 24 was set in 1942. The record coolest high of 34 was set in 1925. 16 of the last 31 lows were 30s. Two lows were in the cooler 20s. 13 lows were in the warmer: 40s (8), 50s (4) and 60s (1).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:51 and sunrise is at 7:20. Sunset is at 17:54 and twilight ends at 18:22. There's a total of 10 hours, 34 minutes of daylight today and 11 hours, 31 minutes between twilights. We are losing two or three minutes of daylight a day. Tomorrow twilight begins at 6:53 and sunrise is at 7:21. The moon is waning gibbous. Illumination was 83% at midnight, will be 79% at noon and 74% at midnight tonight. Moonset is at 11:58 this morning. Moonrise is at 21:13 tonight. Moonset is at 12:45 tomorrow afternoon. Moonlight time is 14 hours, 45 minutes which is six minutes shorter than yesterday.

Halloween is in four days. Election Day is in six days. Veteran's Day is in 15 days. -Bernie-