December 19: ORD

Today is December 19th. It's the 354th day of the year. 12 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 33 and the normal low is 19. The 30-year averages are 32 and 18.

On the warmer side, in 2002 the high was 55 with a low of 34. Five years prior, in 1997, the high was 50 with a low of 31. In 1988 the high was 56 with a low of 23, a 33 degree spread. Other warmer highs were 44 in 1979 and 43 in 1986. Other warmer lows were 33 in 1993, 31 in 1978, 31 in 1987 and 30 in 2001. The record high of 64 and record warmest low of 57 occurred on the same day way back in 1877. 12 of the last 30 highs were 30s. There are nine highs warmer than the 30s and nine colder. On the warmer side, six highs were 40s and three highs were 50s. On the colder side, seven highs were 10s and one high each was in the 0s and 20s.

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 39 with a low of 35, a four degree spread. In 1973 the high was 30 with a low of 24, a six degree spread. In 1972 the high was 37 with a low of 35, a two degree spread. In 1966 the high was 37 with a low of 31, a six degree spread. In 1963 the high was 2 with a low of -14, a cold day. This high of 2 was actually colder than the record coldest high of 5 because 5 degrees occurred at the official station in 1962, Midway Airport. Although the low was -14 in 1963, O'Hare was not the station of record for Chicago at the time, so therefore the record is -14, established in 1983 (when O'Hare was the station of record). In 1961 the high was 36 with a low of 30, a six degree spread.

More recently, we had a small spread of three degrees in 1993 (36/33) and six degrees occurred three times: 1978 (37/31), 1982 (35/29) and 1987 (37/31).

On the cold side, in 1983 the high was the near-record coldest high of 6 with the record low of -14. The record coldest high of 5 was set in 1963. But as I mentioned above, the high in 1963 at O'Hare was 2. It beat the record, but isn't the record. In 2005 the high was 11 with a low of -1. In 1985 the high was 15 with a low of -5. In 1996 the high was 13 with a low of 3. In 1989 the high was 15 with a low of 1. In 1980 the high was 16 with a low of 2. A year later, in 1981, the high was 19 with a low of 1. In 2004 the high was 18 with a low of 4. In 2000 the high was 20 with a low of 7. Another cold low was 6 in 1991. 13 of the last 30 lows were 20s. Six lows were 30s. Seven lows were 0s. Just two lows were negative 0s: one was a negative 10s and one was a 10s low.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:46 and sunrise is at 7:18. Sunset is at 16:23 and twilight ends at 16:55. There's a total of 9 hours, 5 minutes of daylight today and 10 hours, 9 minutes between twilights. Tomorrow twilight begins at 6:47 and sunrise is at 7:18. The moon reached last quarter today at 4:29. Illumination was 52% at midnight, will be 47% at noon and 42% at midnight tonight. Moonset is at 11:42 and moonrise is at 0:50 tomorrow. Moonlight time is 11 hours, 42 minutes today.

Today is a major snow day in O'Hare's history. In 1973, 3.5 inches fell. This was the seventh of eight days of measurable snowfall, part of 17.6 inches that fell. This comprised 94% of the month's total of 18.8 inches.

Christmas Eve is in five days and Christmas Day is in six days. New Year's Eve is in 12 days and New Year's Day is in 13 days. -Bernie-