February 9: ORD

Today is February 9th. It's the 40th day of the year. 326 days remain. It's week 6 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 33 and the normal low is 18. I've calculated the 33-year averages at 33 and 15.

On the warm side, in 1999 the high was 54 with a low of 33. In 1990 the high was 51 with a low of 31. A decade later, in 2000, the high was 48 (our most recent 40s high) with a low of 33. A couple of years later, in 2002, the high was 50 with a low of 30 (our most recent 30s low). Three years ago, in 2009, the high was 53 with a low of 26. In 1996 the high was 47 with a low of 30. Five years earlier, in 1991, the high was 47 with a low of 28. The other warm highs were 54 in 2001, 46 in 1984 and 46 in 1998. The record high of 56 was set way back in 1886, at a time when the official readings were taken adjacent to Lake Michigan. The record warmest low of 47 occurred in 1966 at Midway. 17 of the past 33 highs (52%) were in the: 20s (7) and 30s (10). On the warm side, ten highs (30%) were in the: 40s (5) and 50s (5). Six of the seven years from 1996 through 2002 registered highs in the 40s & 50s. O'Hare's warmest high of the date is 55 in 1966. On the cold side, six highs (18%) were in the: single digits (1) and 10s (a.k.a. teens) (5). O'Hare's coldest high of the date is 4 in 1975.

In looking back through the years to the first February at O'Hare in 1959, the following instances were notable: in 1976 the high was a warm 46 degrees. The following five years in a row (1971-1975) were cold days: In 1975 the high was 4 with a low of -7. In 1974 the high was 24 with a cold low of 2. In 1973 the high was 22 with a cold low of 2. In 1972 the high was 20 with a low of -2. In 1971 the high was 14 with a low of -2. In 1968 the low was a cold 3 degrees. In 1966 the high was 55 with a low of 47, a warm day and year of the record warmest low of 47 (at Midway). In 1965 the high was 49 with a low of 31, a warm day. In 1960 the high was 35 with a low of 29, a six degree spread.

More recently, there were small spreads of four degrees in 1983 (33/29), five degrees two years ago, in 2010 (28/23) and seven degrees in 2005 (31/24).

On the cold side, in 1979 the high was 8 with a low of -6. Three years later, in 1982, the high was 14 with a low of -9 (O'Hare's coldest low of the date). In 1994 the high was 15 with a low of -7. Last year, in 2011, the high was 12 with a low of -2. In 1989 the high was 18 with a low of -4. In 2007 the high was 17 with a low of 2. In 1986 the high was 20 with a low of 2. The prior year, 1985, the high was 23 with a low of 5. The other cold lows were 4 in 2003 and 6 in 1992. The record low of -21 and record coldest high of -8 were set on the same cold day way back in 1899, at a time when the official readings were taken adjacent to Lake Michigan. 23 of the last 33 lows (70%) were in the: single digits (6), 10s (a.k.a. teens) (7) and 20s (10). O'Hare had two stretches of consecutive lows in the 0s, 10s and 20s as follows: six years from 1983 through 1988 and eight years from 2003 through 2010. Even colder, five lows (15%) were in the negative single digits. Prior to 1979, O'Hare's below zero lows are -7 in 1975, -2 in 1971 and -2 in 1972. On the warm side, five lows (15%) were in the 30s. O'Hare's warmest low was 47 in 1966 (same temperature and year of the record warmest low set at Midway).

There was an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1989 the high was 18 with a low of -4, overall 19 degrees BELOW normal. Then in 1990 the high was 51 with a low of 31, overall 15 degrees ABOVE normal.

Today is a major day in Chicago's snow history. In 1981, 0.4 inches fell. This was the first day of a three day, 11.6 inch storm. This storm comprised 73% of the month's total.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:29 and sunrise is at 6:58. Sunset is at 17:18 and twilight ends at 17:47. There's a total of 10 hours, 20 minutes of daylight today and 11 hours, 18 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:28 and sunrise is at 6:57. The moon is waning gibbous, having passed full two days ago as the full Snow (a.k.a. Hunger) moon at 15:54. Illumination was 98% at midnight, will be 95% at noon and 93% at midnight tonight. Moonset is at 7:30 this morning. Moonrise is at 19:49 tonight. Moonset is at 8:00 tomorrow morning. Moonlight time is 11 hours, 41 minutes which is 41 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 in three days. Valentine's Day is in five days. Susan B. Anthony Day is in six days.