February 17: ORD

Today is February 17th. It's the 48th day of the year. 317 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 20. I've calculated the 32-year averages at 35 and 21.

On the warm side, in 1981 the high was 58 with a low of 39. In 1994 the high was 51 with a low of 34. Four years later, in 1998, the high was 43 with a low of 39, a mere four degree spread. Other warm highs were 47 in both 1995 and three years ago (2008). There were four other warm lows: 36 degrees in 1992, 35 degrees in 1984, 33 degrees in 1983 and 32 degrees in 1982. The record high of 60 was set way back in 1880. The record warmest low of 42 was set way back in 1890. 21 of the last 32 highs (66%) were in the: 30s (13) and 40s (8). On the warmer side, two highs (6%) were in the 50s. On the colder side, nine highs (28%) were in the: 10s (a.k.a. teens) (3) and 20s (6).

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 19 with a low of -2, a cold day. In 1976 the high was 42 with a warm low of 36, a six degree spread. In 1975 the high was 36 with a warm low of 33, a three degree spread. In 1973 the high was 21 with a low of 2, a cold day. In 1971 the high was 46 with a warm low of 36, a warm day. In 1968 the high was 22 with a low of 1, a cold day. In 1967 the low was a cold 8 degrees. In 1966 the high was 24 with a cold low of 7, a cold day. In 1962 the high was 32 with a low of 27, a five degree spread. In 1961 the high was 50 with a low of 37, a warm day.

More recently, there were small spreads of four degrees on two occasions: 1983 (37/33) and 1992 (40/36). There was a small spread of five degrees in 1982 (37/32). Spreads of six degrees occurred in: 1986 (36/30) and last year (32/26). No large spreads (30 degrees or more) have occurred.

On the cold side, in 1980 the high was 14 with a low of -5. The year prior, 1979, the high was 12 with a low of 3. In 1993 the high was 20 with a low of 0. In 2001 the high was 19 with a low of 6. Five years later, in 2006, the high was 24 with a low of 3. The record low of -11 and record coldest high of 1 were set on the same cold day back in 1903. 26 of the last 32 lows (81%) were in the: 10s (a.k.a. teens) (8), 20s (9) and 30s (9). Even colder, six lows (19%) were in the: single digits (5) and negative single digits (1).

Today is not major day in Chicago's snow history.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:18 and sunrise is at 6:47. Sunset is at 17:28 and twilight ends at 17:57. There's a total of 10 hours, 41 minutes of daylight today and 11 hours, 39 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:17 and sunrise is at 6:46. The moon is waxing gibbous, heading towards the full Snow or Hunger moon tomorrow morning at 2:36. Illumination was 98% at midnight, will be 99% at noon and 100% at midnight tonight. Moonset is at 6:01 this morning. Moonrise is at 17:05 this afternoon. Moonset is at 6:33 tomorrow morning. Moonlight time is 12 hours, 56 minutes which is 43 minutes shorter than yesterday.

President's Day is in four days and Washington's Birthday is in five days. -Bernie-