December 5: ORD

Today is December 5th. It's the 339th day of the year. 26 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 38 and the normal low is 24. I've calculated the 32-year averages at 39 and 24.

On the warm side, in 1998 the high was 62 with the record warmest low of 55, a seven degree spread. Three years later, in 2001, the high was the record high of 68 with a low of 44. In 1982 the high was 63 with a low of 38. Three years prior, in 1979, the high was 54 with a low of 37. In 1980 the high was 55 with a low of 36. The 50s highs, as you can see, occurred in back to back years quite some time ago. In 1994 the high was 49 with a low of 37. Over the last 32 years, 20 highs (62%) were in the: 30s (11) and 40s (9). Five highs were in the warmer: 50s (2) and 60s (3). Seven highs were in the cold: 10s (1) and 20s (6).

In looking back through the years to the first December at O'Hare in 1958, the following instances were notable: in 1976 the low was a cold 9 degrees. In 1975 the high was 64 with a low of 46, a warm day. In 1972 the high was 30 with a low of 24, a six degree spread. In 1971 the high was 40 with a warm low of 36, a four degree spread. In 1967 the high was 48 with a warm low of 39, a warm day. In 1966 the high was 39 with a low of 34, a five degree spread. In 1965 the high was a warm 51 degrees. In 1964 the high was 23 with a low of 8, a cold day. In 1960 the high was 61 with a low of 41, a warm day. In 1958 the low was a cold 11 degrees.

More recently, there were no large spreads. There were small spreads of three degrees in 1996 (34/31), five degrees in 1978 (36/31), five degrees in 1983 (37/32) and six degrees in 1997 (29/23).

On the cold side, in 2005 the high was 17 with the record low of 4. Two years ago the high was 23 with a low of 7. Three years ago the high was 30 with a low of 9. In 2002 the high was 24 with a low of 15. In 1992 the high was 25 with a low of 14. The year prior, 1991, the high was 33 with a low of 6. In 1984 the high was 28 with a low of 11. Other cold lows were 7 in 2006 and 12 in 2000. The record coldest high of 15 was set way back in 1895. 25 of the last 32 lows (78%) were: 10s (a.k.a. teens)(7), 20s (7) and 30s (11). Five lows were in the cold 0s (a.k.a. single digits). Two lows were in the warmer: 40s (1) and 50s (1). Four of the five single digit lows occurred four years in a row from 2005 to 2008, including the record low.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:35 and sunrise is at 7:07. Sunset is at 16:21 and twilight ends at 16:53. There's a total of 9 hours, 14 minutes of daylight today and 10 hours, 18 minutes between twilights. We are losing a minute or two of daylight per day. Tomorrow twilight begins at 6:36 and sunrise is at 7:08. The moon is new today at 11:36. Illumination was 0% at midnight, will be 0% at noon and 0% at midnight tonight. Moonrise is at 7:09 this morning. Moonset is at 16:17 this afternoon. Moonrise is at 8:07 tomorrow morning. Moonlight time is 9 hours, 8 minutes which is 13 minutes shorter than yesterday and is at it's minimum.

Pearl Harbor Day is in two days. Bill of Rights Day is in ten days. -Bernie-