Tuesday, February 16, 2010

February 15: ORD

Today is February 15th. It's the 46th day of the year. 319 days remain. It's week 7 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 35 and the normal low is 19. I've calculated the 31-year averages at 34 and 21.


On the warm side, in 1984 the high was 60 with a low of 33. Fifteen years later, in 1999, the high was 55 with a low of 34. A year earlier, in 1998, the high was 53 with a low of 32. In 1981 the high was 45 with a low of 33. In 2002 the high was 42 with a low of 35, a seven degree spread. Twenty years before that, in 1982, the high was 43 with a low of 34. Other warm lows were: 33 (1992), 33 (2005) and 32 in 2006. The record high of 69 was set in 1954. The record warmest low of 43 occurred in 1976. A warm low of note was 40 in 1954. 24
of the last 31 highs were 20s (6), 30s (11) and 40s (7). On the warmer side, two highs were 50s (2) and one was a 60. On the colder side, four highs were 10s (a.k.a. teens).

In looking back through the years to the first February at O'Hare in 1959, the following instances were notable: In 1978 the high was a cold 22 degrees with a low of 8, a cold day. In 1976 the high was 65 with a low of 40, a warm day. In 1975 the high was 34 with a low of 27, a seven degree spread. In 1969 the high was 30 with a low of 25, a five degree spread. In 1967 the high was a warm 49 with a low of 13, a 36 degree spread. In 1963 the high was 18 with a low of -9, a cold day. In 1962 the high was 34 with a low of 29, a five degree spread. In 1961 the high was a warm 59 with a low of 28, a 31 degree spread and warm day.

More recently, there were small spreads of four degrees in 1992 (37/33), five degrees in 1990 (32/27), six degrees in both 1987 (26/20) and 2001 (32/26) and seven degrees in 1979 (27/20).

On the cold side, in 1985 the high was 12 with a low of 0. Six years later, in 1991, the high was 13 with a low of 3. Three years ago the high was 14 with a low of 2. In 1986 the high was 18 with a low of -1. In 2004 the high was 22 with a low of 6. The record low of -9 was set back in 1905 and the record coldest high of 5 was set back in 1920. 25 of the last 31 lows have been: 10s (a.k.a. teens) (8), 20s (8) and 30s (9). Even colder, five lows have been single digits and one was in the negative single digits.

Today is a major day in Chicago's snow history. In 1990, 1.4 inches fell. This was the second day of a two day, 9.7 inch storm known as the Valentine's Day Blizzard. This storm comprised 71% of the month's total of 13.6 inches.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 6:21 and sunrise is at 6:50. Sunset is at 17:26 and twilight ended at 17:55. There's a total of 10 hours, 36 minutes of daylight today and 11 hours, 34 minutes between twilights. Tomorrow twilight begins at 6:20 and sunrise is at 6:48. The moon is waxing crescent. Illumination was 1% at midnight, will be 3% at noon and 4% at midnight tonight. Moonrise was at 7:12. Moonset is at 19:17 tomorrrow. Moonlight time is 12 hours, 5 minutes which is 39 minutes longer than yesterday.

Susan B. Anthony Day and President's Day are today. -Bernie-

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