December 4: ORD

Today is December 4th. It's the 339th day of the year. 27 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. Observations have been official at O'Hare since Thursday, January 17, 1980.

According to the National Climatic Data Center (NCDC), the normal high is 38 and the normal low is 24. The 30-year averages are 38 and 25.

On the warm side, in 1998 the high was the record high of 66 with the record warmest low of 55. In 2001 the high was 62 with a low of 54. In 1999 the high was 54 with a low of 44. Five years earlier, in 1994, the high was 56 with a low of 39. In 1982 the high was 47 with a low of 38. Other warm lows were 34 in 2003 and 33 ten years earlier in 1993. Having a low above freezing is special this time of the year. 20 of the last 30 highs were 30s (12) and 40s (8). Five highs were 20s, two highs were 50s and two highs were 60s. 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 1971 the high was 41 with a low of 34, a seven degree spread. In 1968 the high was 41 with a low of 35, a six degree spread. In 1965 the high was 38 with a low of 32, a six degree spread. In 1961 the high was 62 with a low of 31, a bonus 60s day.

More recently, the spread was five degrees in 1983 (37/32), five degrees in 2003 (39/34) and six degrees in 1997 (35/29).

On the cold side, in 1991 the high was the record coldest high of 13 with a low of 3. The former record coldest high was 18 way back in 1895. Two years ago the high was 26 with a low of 6. In 1984 the high was 24 with a low of 12. In 2002 the high was 28 with a low of 10. Three years after that, in 2005, the high was 28 with a low of 12. This year will be one of the coldest as the low will be near 10 and the high is predicted to be in the low to mid 20s. Another cold low was 8 in 1978. The record low of -1 was set way back in 1893. 12 of the last 30 lows were in the 20s. Seven lows were 10s, five lows were 30s, three lows were 0s, two lows were 50s and one low was in the 40s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:35 and sunrise is at 7:06. Chicago's twilight and sunrise times are four minutes earlier. Sunset is at 16:21 and twilight ends at 16:53. Chicago's sunset is a minute earlier and end of twilight time is two minutes earlier. There's a total of 9 hours, 15 minutes of daylight today and 10 hours, 18 minutes between twilights. Tomorrow twilight begins at 6:35 and sunrise is at 7:07. The moon is waxing crescent and will reach first quarter tomorrow at 15:26. Illumination was 34% at midnight, will be 39% at noon and 44% at midnight tonight. Moonrise is at 11:40 and moonset is at 22:53. Moonlight time is 11 hours, 13 minutes.

Pearl Harbor Day is in three days. A sister of mine, Regina, will celebrate a birthday in ten days and Bill of Rights day is in 11 days. -Bernie