December 31: ORD

Today is December 31st. It's the 366th day of the year. No days remain. It's week 53 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 30 and the normal low is 16. The 30-year averages are 35 and 21.

On the warm side, in 2006 the high was 56 with the record warmest low of 43. In 2004 the high was 56 with a low of 29. These two highs of 56 were the warmest at O'Hare since 1965 when the high was 58. In 2002 the high was 41 with a low of 28. In 2005 the high was 37 with a low of 32, a five degree spread. Other warm highs were 44 in 1979, 42 in 2003 and 41 in 1999. Other warm lows were 32 (1980, 1995), 31 (1984, 1991) and 30 in 1986. The record high of 68 was set way back in 1875. 18 of the last 30 highs were 30s. On the warmer side, six highs were: 40s (4) and 50s (2). On the colder side, six highs were: 20s (4) and 10s (2).

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 33 with a low of 30, a three degree spread. In 1976 the high was 6 with a low of -8, a cold day. In 1974 the high was 36 with a low of 34, a two degree spread. In 1967 the high was 25 with a low of -11, a 36 degree spread. In 1965 the high was 58 with a low of 31, a warmer day than most. In 1963 the high was 17 with a low of -14, a 31 degree spread and cold. In 1958 the high was 30 with a low of 24, a six degree spread.

More recently, we had small spreads of two degrees in 1980 (34/32), three degrees in 1991 (34/31), four degrees in 1995 (36/32), five degrees in 1984 (36/31), five degrees in 1989 (33/28) and six degrees in 1986 (36/30). We've had one large spread. It turned out to be a normal day. In 1987 the spread was 32 degrees as the high was 39 with a low of 7.

Before today, seven of the last 11 years were above normal including the last six years straight. We've had the best warmth mother nature could provide the prior six years. Last year (although the coldest of the six) was 33/28. Two years ago was the warmest ever of the past 30 years, peaking at 56. Three years ago made the top four warmest because the spread was very small. Four years ago we had another remarkable high of 56, occurring at 47 minutes past midnight. Five years ago the high was 42. Six years ago the high was 41. Looking further back, seven and eight years ago were exceptions, having lows of seven degrees and very much below normal. Nine years ago, in 1999, the high was 41. The one other high in the 40s occurred in 1979 when it hit 44 degrees. This year, since the high is predicted to be 21 at O'Hare today (18 in Crystal Lake) and the low was at least 12 at O'Hare this morning (at least 9 in Crystal Lake), it will finish below normal. That makes only seven of the last 12 years above normal (down to 58%).

On the cold side, in 1990 the high was 16 with a low of 1. Another cold low was 6 in 1983 and another cold high was 17 in 1998. The record low of -10 was set in 1967 at Midway (it was -11 at O'Hare). The record coldest high of 5 was set in 1976 at Midway (it was 6 at O'Hare). 13 of the last 30 lows were 20s. On the colder side, seven lows were 0s and three lows were 10s. On the warmer side, six lows were 30s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:50 and sunrise is at 7:22. Sunset is at 16:31 and twilight ends at 17:03. There's a total of 9 hours, 9 minutes of daylight today and 10 hours, 13 minutes between twilights. Tomorrow twilight begins at 6:50 and sunrise is at 7:22. The moon is waxing crescent. Illumination was 12% at midnight, will be 16% at noon and 19% at midnight tonight. Moonrise was at 9:44 and moonset is at 20:45. Moonrise is at 10:06 tomorrow. Moonlight time is 11 hours, 1 minute today.

Today is a major snow day in O'Hare's history. Back in 1978, 10.1 inches fell. This was day four of a four day, 16.8 inch storm. The total snowfall of December 1978 was 35.1 inches at O'Hare.

New Year's Eve is today (as is my best friend's birthday (Christopher)) and New Year's Day is tomorrow. Martin Luther King, Jr. Day is in two weeks, five days and my brother will be celebrating a birthday in three weeks, three days. -Bernie-