December 29: ORD

Today is December 29th. It's the 363rd day of the year. Two days remain. It's week 52 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 31 and the normal low is 16. I've calculated the 32-year averages at 34 and 21.

On the warm side, in 1984 the high was the record high of 63 with a low of 28, a 35 degree spread. In 2006 the high was 50 with a low of 40. In 1992 the high was 44 with a low of 39, a five degree spread. In 2003 the high was 47 with a low of 30. In 1979 the high was 52 with a low of 22, a 30 degree spread. Two years ago the high was 43 with a low of 29. In 1999 the high was 45 with a low of 26. Other warm lows were 32 in 1989, 32 in 2005, 31 in 1994 and 30 in 1991. The record warmest low of 42 was set way back in 1884. 13 of the last 32 highs (41%) were 30s. On the warmer side, ten highs (31%) were: 40s (7), 50s (2) and 60s (1). On the colder side, nine highs (28%) were: single digits (1), 10s (aka teens)(3) and 20s (5).

In looking back through the years to the first December at O'Hare in 1958, the following instances were notable: in 1976 the high was 7 with a low of -7, a cold day. In 1974 the high was 38 with a warm low of 34, a four degree spread and warm day. In 1972 the high was 44 with a low of 34, a warm day. In 1969 the high was 30 with a low of 27, a three degree spread. In 1967 the low was a cold 4 degrees. In 1965 the high was 41 with a low of 33, a warm day. In 1964 the high was 44 with a low of 31, another warm day. In 1963 the high was 8 with a low of -8, a cold day. In 1962 the high was 34 with a cold low of 2, a 32 degree spread. In 1961 the high was 14 with a low of 1, a cold day. In 1958 the low was a warm 28 degrees.

More recently, we had a small spread of four degrees in 1986 (33/29), five degrees in 1991 (35/30), five degrees in 2005 (37/32), six degrees in 1989 (38/32), seven degrees in 1980 (36/29), seven degrees in 1982 (24/17) and seven degrees in 1994 (38/31).

On the cold side, in 1983 the high was the record coldest high of 2 with a low of -8. A couple of years earlier, in 1981, the high was 18 with a low of -1. Four years later, in 1985, the high was 18 with a low of 7. Another cold high was 19 in 2001. The record low of -15 was set way back in 1880. 13 of the last 32 lows (41%) were 30s. On the colder side, 12 lows (37%) were: negative single digits (2), single digits (6) and 10s (aka teens)(4). On the warmer side, seven lows (22%) were: 30s (6) and 40s (1).

Today is a major snow day in O'Hare's history. Back in 1978, 2.3 inches fell. This was day two of a four day, 16.8 inch storm.

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 16:29 and twilight ends at 17:01. There's a total of 9 hours, 7 minutes of daylight today and 10 hours, 11 minutes between twilights. We lost a minute of daylight from yesterday. Tomorrow twilight begins at 6:50 and sunrise is at 7:22. The moon reached last quarter two nights ago at 22:18 and is waning crescent. Illumination was 38% at midnight, will be 33% at noon and 28% at midnight tonight. Moonrise is at 1:28 this morning. Moonset is at 12:01 this afternoon. Moonrise is at 2:40 tomorrow morning. Moonlight time is 10 hours, 33 minutes which is 42 minutes less than yesterday.

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