December 22: ORD

Today is December 22nd. It's the 357th day of the year. Nine days remain. It's week 51 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 32 and the normal low is 18. The 30-year averages are 34 and 20.

On the warmer side, in 1979 the high was 50 with a low of 44, a six degree spread. Two years ago the high was 54 with a low of 40. A year ago the high was 50 with a low of 36. In 2003 the high was 47 with a low of 36. In 2001 the high was 49 with a low of 33. In 1994 the high was 52 with a low of 27. Other warm highs were 48 in 1982 and 45 in 1988. Other warmer lows were 33 in 1997, 31 in 1981 and 30 in 1987. The record high of 57 occurred in 1957. The record warmest low of 50 was set in 1941. 18 of the last 30 highs were 30s (11) and 40s (7). On the warmer side, four highs were in the 50s. On the colder side, four highs were in the 10s, two highs were 0s and two highs were 20s.

In looking back through the years to the first December at O'Hare in 1958, the following instances were notable. In 1974 the high was 42 with a low of 3, a 39 degree spread. In 1972 the high was 33 with a low of 31, a two degree spread. In 1970 the high was 36 with a low of 34, a two degree spread. In 1963 the high was 19 with a low of -13, a 32 degree spread and cold! In 1961 the high was 35 with a low of 31, a four degree spread.

More recently, we had small spreads of two degrees in 1981 (33/31), four degrees in 1997 (37/33), five degrees in 2002 (30/25) and seven degrees in 1991 (36/29). A large spread of 32 degrees occurred in 2005 (38/6).

On the cold side, in 1989 the high was the record coldest high of 3 with a low of -12. In 2000 the high was 7 with a low of -9. In 1983 the high was 19 with a low of -18, a 37 degree spread. In 1998 the high was 14 with a low of 5. In 2004 the high was 14 with a low of 8. In 1999 the high was 17 with a low of 8. The record low of -21 was set way back in 1872. 25 of the last 30 lows were 0s (5), 10s (5), 20s (9) and 30s (6). On the warmer side, two lows were 40s. On the colder side, two lows were negative 10s and one low was a negative zero.

It is very cold today. All around the Chicago area, the lows this morning are in the negative zeros.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:48 and sunrise is at 7:19. Chicago's sunrise and twilight times are four and three minutes earlier respectively. Sunset is at 16:25 and twilight ends at 16:57. Chicago's sunset and end of twilight times are a minute and two minutes earlier respectively. There's a total of 9 hours, 6 minutes of daylight today and 10 hours, 9 minutes between twilights. Tomorrow twilight begins at 6:48 and sunrise is at 7:20. The moon is waning crescent. Illumination was 23% at midnight, will be 19% at noon and 16% at midnight tonight. Moonrise was at 3:00 and moonset is at 12:53. Moonrise is at 4:04 tomorrow. Moonlight time is 9 hours, 53 minutes today. The Winter Solstice was yesterday at 6:04.

Today is a major snow day in O'Hare's history. In 1969, 1.2 inches fell. This was the second of four days of measurable snowfall, part of a total of 13.5 inches during the period.

Christmas Eve is in two days and Christmas Day is in three days. New Year's Eve is in nine days and New Year's Day is in ten days. -Bernie-