February 14: ORD

Today is February 14th. It's the 45th day of the year. 321 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. Before this, the official site was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 35 and the normal low is 20. I've calculated the 33-year averages at 34 and 21.

On the warm side, in 2005 the high was 49 with a low of 37 (O'Hare's warmest low of the date). In 1984 the high was 55 with a low of 28. In 2006 the high was 56 with a low of 24, a 32 degree spread. These were the only 50s highs in O'Hare's history for the date. The other warm high was 47 in 1999. The other warm low was 33 in 1998. The record high of 62 and record warmest low of 43 were set on the same warm day in 1954. 25 of the past 33 highs (76%) were in the: 30s (17) and 40s (8). O'Hare had 15 consecutive 30s & 40s highs from 1991 through 2005. On the warm side, two highs (6%) were in the 50s. On the cold side, six highs (18%) were in the: 10s (a.k.a. teens) (1) and 20s (5).

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 27 with a low of 21, a six degree spread. In 1977 the high was 30 with a low of 23, a seven degree spread. In 1976 the high was a warm 47 degrees. In 1974 the high was 29 with a low of 24, a five degree spread. In 1971 the low was a cold 5 degrees. In 1970 the high was 23 with a low of 8, a cold day. In 1967 the high was 47 with a low of 35, a warm day. In 1964 the low was a cold 7 degrees. In 1963 the high was 20 with a low of -3, a cold day. In 1961 the high was a warm 49 with a low of 28, a warm day.

More recently, there were small spreads of two degrees in 1990 (28/26), three degrees in 1992 (34/31). The lone large spread was 30 degrees in 1994 (44/14).

On the cold side, in 1985 the high was 19 (O'Hare's coldest high of the date) with a low of 4. In 2007 the high was 21 with a low of 7. The other cold lows were 6 in both 1986 and 1995. The record low of -11 was set back in 1905, at a time when the official readings were taken adjacent to Lake Michigan. The record coldest high of 8 occurred in 1943 at Midway. 25 of the last 33 lows (76%) were in the: 10s (a.k.a. teens) (11) and 20s (14). O'Hare had consecutive lows in the 10s & 20s as follows: seven from 1977 through 1984 and six from 1999 through 2004. Even colder, five lows (15%) were in the single digits. O'Hare's coldest low was -3 in 1963. O'Hare also had single-digit lows of 5 in 1971 and 7 in 1964. On the warm side, three lows (9%) were in the 30s.

There were two instances of back-to-back years in which temperatures were just about as opposite as they can be. In the first instance, in 1984 the high was 55 with a low of 28, overall 14.5 degrees ABOVE normal. Then in 1985 the high was 19 with a low of 4, overall 15.5 degrees BELOW normal. In the second instance, in 2006 the high was 56 with a low of 24, overall 13 degrees ABOVE normal. Then in 2007 the high was 21 with a low of 7, overall 13 degrees BELOW normal.

Today is a major day in Chicago's snow history. In 2007, 1.4 inches fell. This was the third day of a three day, 11.6 inch storm. In 1990, 8.3 inches fell. This was the first day of a two day, 9.7 inch storm known as the Valentine's Day Blizzard.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:23 and sunrise is at 6:52. Sunset is at 17:24 and twilight ends at 17:53. There's a total of 10 hours, 32 minutes of daylight today and 11 hours, 30 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 6:21 and sunrise is at 6:50. The moon reaches last quarter today at 11:04. Illumination was 55% at midnight, will be 50% at noon and 44% at midnight tonight. Moonrise is at 0:39 this morning. Moonset is at 10:26 this morning. Moonrise is at 1:47 tomorrow morning. Moonlight time is 9 hours, 47 minutes which is four minutes longer than yesterday.

Winter began December 1st and runs for 102 days through March 11th. High temperatures in this period are usually in the 20s and 30s. Highs in the 40s and 50s occur infrequently. Valentine's Day is today. Susan B. Anthony Day is tomorrow. President's Day is in six days.