December 11: ORD

Today is December 11th. It's the 346th day of the year. 20 days remain. It's week 50 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. Observations have been official at O'Hare since Thursday, January 17, 1980.

According to the National Climatic Data Center (NCDC), the normal high is 36 and the normal low is 22. The 30-year averages are 36 and 22.

On the warm side, in 1979 the high was 56 with a low of 34. In 1990 the high was 55 with a low of 32. In 1987 the high was 48 with a low of 34. Two years ago the high was 45 with a low of 37. Other warm highs were 49 in both 1991 and 1998. Another warm high was 48 in 2001. Other warm lows were 36 in 1996 and 33 in 1983. The record high of 61 was set back in 1949. The record warmest low of 50 was set in 1965. At O'Hare this low was 51. 21 of the last 30 highs were 30s (13) and 40s (8). Five highs were 20s, two highs were 50s, one high was in the 0s and one high was in the 10s.

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 23 with a low of -7, a 30 degree spread and cold. Also, this low of -7 was colder than the record low of -5 but since it occurred at O'Hare, it was unofficial. In 1975 the high was 38 with a low of 35, a 3 degree spread. In 1972 the high was 21 with a low of -13, a 34 degree spread and very cold day. Once again, this low of -13 was colder than the record but unofficial. In 1970 the high was 40 with a low of 35, a five degree spread. In 1967 the high was 40 with a low of 37, a three degree spread. In 1965 the high was 56 with a low of 51, a five degree spread. The low of 51 was the unofficial record warmest low. In 1964 the high was 40 with a low of 33, a seven degree spread. In 1963 the high was 30 with a low of 25, a five degree spread. In 1962 the high was 7, a degree higher than the record coldest high of 6. The low was -4, also a degree higher than the record low of -5.

More recently, we had small spreads of three degrees in 1996 (39/36), three degrees in 1997 (35/32), five degrees in 1983 (38/33), five degrees in 2004 (37/32) and six degrees last year (33/27).

On the cold side, in 1995 the high was 8 with a low of 1, a cold day and seven degree spread. In 1988 the high was 18 with a cold low of 3. In 1982 the high was 26 with a low of 9. Two years earlier, in 1980, the high was 24 with a low of 11. Other cold lows were 7 in 2005, 11 in 1989 and 12 in 1986. Another cold high was 24 in 1994. The record low of -5 was set in 1972 and the record coldest high of 6 was set in 1962. 26 of the last 30 lows were 10s (9), 20s (7) and 30s (10). Four lows were 0s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:41 and sunrise is at 7:12. Chicago's twilight begins four minutes earlier and sunrise is three minutes earlier. Sunset is at 16:21 and twilight ends at 16:53. Chicago's sunset is a minute earlier and twilight ends two minutes earlier. There's a total of 9 hours, 9 minutes of daylight today and 10 hours, 12 minutes between twilights. Tomorrow twilight begins at 6:41 and sunrise is at 7:13. The moon is waxing gibbous. The full Cold moon is tomorrow at 10:37. Illumination was 97% at midnight, will be 98% at noon and 100% at midnight tonight. Moonset was at 6:11 and moonrise is at 15:09. Moonset is at 7:26 tomorrow. Moonlight time is 15 hours, 2 minutes today.

Today is a major snow day in O'Hare's history. In 2000, 9.5 inches fell. This was the second day of a two day storm of 9.6 inches.

A sister of mine, Regina, will celebrate a birthday in three days and Bill of Rights day is in four days. Christmas Eve is in 13 days and Christmas Day is in two weeks. -Bernie-