February 12: ORD

Today is February 12th. It's the 43rd day of the year. 323 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 34 and the normal low is 19. I've calculated the 33-year averages at 31 and 16.

On the warm side, in 1984 the high was the record high of 62 with a low of 45 (O'Hare's warmest February 12th). The record high of 62 was originally set way back in 1882. In 2005 the high was 51 with a low of 33. In 1990 the high was 54 with a low of 23. The other warm low was 31 in 1998. The record warmest low of 50 was set way back in 1882. Both that and the original record high (62 in 1882) were set at a time when the official readings were taken adjacent to Lake Michigan. So overall, the warmest February 12 occurred in 1882. 24 of the past 33 highs (73%) were in the: 20s (9) and 30s (15). O'Hare had six consecutive 20s & 30s highs from 2006 through 2011. On the warm side, five highs (15%) were in the: 40s (2), 50s (2) and 60s (1). O'Hare's only other 50s high was 56 in 1976. On the cold side, four highs (12%) were in the 10s (a.k.a. teens). Our most recent 10s high was 16 in 1995. The 10s highs occurred (except for 19 in 1960) from 1981 through 1995. In the 53 year history of O'Hare, only four highs were 50 degrees or higher. This is only 7.5% of the years which is on average once every 13 and a quarter years.

In looking back through the years to the first February at O'Hare in 1959, the following instances were notable: In 1977 the high was 45 with a warm low of 36, a warm day. In 1976 the high was 56 with a low of 38, a warm day. In 1974 the high was a warm 47 degrees. In 1970 and 1968, the highs were a cold 22 degrees. In 1967 the high was 20 with a low of -17, a 37 degree spread and cold day. In 1966 the high was a warm 48 degrees. In 1963 the high was 22 with a low of -9, a 31 degree spread and cold day. In 1962 the high was 35 with a warm low of 31, a four degree spread. In 1960 the high was 19 with a low of 6, a cold day.

More recently, there were small spreads of three degrees in 1979 (22/19), four degrees in 1993 (31/27), six degrees in 2007 (31/25) and seven degrees in 2006 (30/23).

On the cold side, in 1981 the high was 12 with a low of -11. Five years later, in 1986, the high was 11 (O'Hare's coldest high of the date) with a low of -4. In 1995 the high was 16 with a low of -2. In 1988 the high was 17 with a low of -1. In 2003 the high was 21 with a low of 4. In 1980 the high was 23 with a low of 4. The other cold highs were 22 in both 1979 and 2008. The record low of -17 and record coldest high of 3 were set on the same cold day way back in 1899, at a time when the official readings were taken adjacent to Lake Michigan. 22 of the last 33 lows (67%) were in the: 10s (a.k.a. teens) (14) and 20s (8). There were six consecutive 10s & 20s lows from 1989 through 1994. Even colder, seven lows (21%) were in the: negative 10s (a.k.a. negative teens) (1), negative single digits (3) and single digits (3). O'Hare's coldest low was -17 in 1967. The other sub-zero low was -9 in 1963. On the warm side, four lows (12%) were in the: 30s (3) and 40s (1).

Today is a major day in Chicago's snow history. In 2007, 1.4 inches fell. This was the first day of a three day, 11.6 inch storm.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:25 and sunrise is at 6:54. Sunset is at 17:21 and twilight ends at 17:50. There's a total of 10 hours, 27 minutes of daylight today and 11 hours, 25 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:24 and sunrise is at 6:53. The moon is waning gibbous. Illumination was 77% at midnight, will be 72% at noon and 67% at midnight tonight. Moonset is at 9:05 this morning. Moonrise is at 23:28 tonight. Moonset is at 9:43 tomorrow morning. Moonlight time is 9 hours, 37 minutes which is 39 minutes shorter 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. Abraham Lincoln's Birthday is today. Valentine's Day is in two days. Susan B. Anthony Day is in three days.