December 8: ORD

Today is December 8th. It's the 342nd day of the year. 23 days remain. It's week 49 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 37 and the normal low is 23. I've calculated the 32-year averages at 37 and 22.

On the warm side, in 1987 the high was 58 with a low of 38. In 1991 the high was 60 with a low of 36. Another warm high was 49 in 1999. Other warm lows were 36 in 1986, 36 in 2004 and 35 in 2003. The record high of 64 and record warmest low of 53 were set on the same day in 1946. Over the last 32 years, 23 highs (72%) were in the: 30s (12) and 40s (11). Our most recent 40s high was 41 in 2004. Seven highs were in the cold 20s. Two highs were in the warmer: 50s (1) and 60s (1).

In looking back through the years to the first December at O'Hare in 1958, the following instances were notable: in 1977 the high was a cold 24 with a low of 13, a cold day. In 1976 the high was 14 with a low of 4, a cold day. In 1975 the high was 33 with a low of 28, a five degree spread. In 1973 the high was 34 with a low of 28, a six degree spread. In 1972 the high was 28 with a low of 21, a seven degree spread. In 1971 the high was 44 with a warm low of 40, a four degree spread and warm day. In 1970 the high was a warm 49 degrees. In 1967 the high was 40 with a warm low of 38, a two degree spread. In 1966 the high was 61 with a low of 37, a warm day. In 1964 the low was a cold 10 degrees. In 1958 the high was 13 with a low of -7, a cold day. That low of -7 unofficially ties the record low.

More recently, there were no large spreads of 30 degrees or more. There were small spreads of three degrees in 1996 (30/27), four degrees in 1992 (28/24), five degrees in 1986 (41/36), five degrees in 1997 (31/26), five degrees in 2004 (41/36) and six degrees in 1983 (26/20).

On the cold side, in 2006 the high was 21 with a low of 4. A year earlier, in 2005, the high was 28 with a low of 3. In 1978 the high was 21 with a low of 11. In 1995 the high was 30 with a low of 4. Five years later, in 2000, the high was 29 with a low of 7. In 2007 the high was 24 with a low of 13. The record low of -7 was set way back in 1882. The record coldest high of 8 occurred back in 1927. 13 of the last 32 lows (41%) were 20s. 11 lows (34%) were in the cold 0s (4) and 10s (a.k.a. teens)(7). Eight lows (25%) were in the warmer 30s. Our most recent 30s lows were 35 in 2003 and 36 in 2004.

Two recent days (December 5 & 6) have each been the third coldest of the past 33 years. In other words, they were in the top 9% of cold days for each date. Yesterday (December 7) was the fourth coldest of the date, in the top 12%.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:38 and sunrise is at 7:09. Sunset is at 16:21 and twilight ends at 16:53. There's a total of 9 hours, 12 minutes of daylight today and 10 hours, 15 minutes between twilights. We are losing a minute of daylight per day. Tomorrow twilight begins at 6:39 and sunrise is at 7:10. The moon is waxing crescent. Illumination was 7% at midnight, will be 10% at noon and 13% at midnight tonight. Moonrise was at 9:35 this morning. Moonset is at 19:24 tonight. Moonrise is at 10:07 tomorrow morning. Moonlight time is 9 hours, 49 minutes which is 24 minutes longer than yesterday.

Bill of Rights Day is in seven days. -Bernie-