February 19: ORD

Today is February 19th. It's the 50th day of the year. 316 days remain. It's week 8 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 37 and the normal low is 21. I've calculated the 33-year averages at 39 and 23.

On the warm side, in 1994 the high was 60 with the record warmest low of 51. In 1981 the high was 61 with a low of 33. Those were O'Hare's only 60s highs of the date. Two years later, in 1983, the high was 55 with a low of 33. In 2002 the high was 46 with a low of 38, our most recent 30s low. That low of 38 (along with a low of 38 in 1971) were O'Hare's second warmest lows of the date. The other warm lows were 37 in 1998, 34 in 1992 and 33 in 1980. The record high of 65 was set back in 1930, at a time when the official readings were taken adjacent to Lake Michigan. 18 of the past 33 highs (55%) were in the 40s. On the warm side, three highs (9%) were in the: 50s (1) and 60s (2). O'Hare also had a high of 56 in 1971. On the cold side, 12 highs (36%) were in the: 10s (a.k.a. teens) (2), 20s (3) and 30s (7). O'Hare's coldest high was 10 in 1959. O'Hare also had a cold high of 19 the next year, in 1960.

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 22 with a low of -4, a cold day. In 1973 the high was 35 with a low of 31, a four degree spread. In 1971 the high was 56 with a low of 38, a warm day. In 1970 the high was 22 with a low of 3, a cold day. In 1966 the high was 20 with a low of 1, a cold day. In 1964 the high was 35 with a low of 29, a six degree spread. In 1963 the high was 36 with a low of 29, a seven degree spread. In 1960 the high was 19 with a low of 7, a cold day. In 1959 the high was 10 with a low of -2, a cold day.

More recently, there were small spreads of six degrees in 1982 (36/30), six degrees in 1998 (43/37), seven degrees in 1980 (40/33) and seven degrees in 1992 (41/34).

On the cold side, in 1979 the high was 15 with a low of -9, O'Hare's coldest low. That low of -9 is colder than the official record low of -7 which was set in 1936 (at a time when the official readings were taken adjacent to Lake Michigan). In 2008 the high was 14 with a low of 4. Two years prior, in 2006, the high was 20 with a low of 1. In 1993 the high was 24 with a low of 5. Three years ago, in 2009, the high was 23 with a low of 11. The record coldest high of 9 was set in 1936 (the same year as the record low). 28 of the last 33 lows (85%) were in the: 10s (a.k.a. teens) (6), 20s (11) and 30s (11). On the cold side, four lows were in the: negative single digits (1) and single digits (3). O'Hare had pre-1979 sub-zero lows of -4 in 1978 and -2 in 1959. On the warm side, one low was in the 50s.

There was an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1993 the high was 24 with a low of 5, overall 14.5 degrees BELOW normal. Then in 1994 the high was 60 with a low of 51, overall 26.5 degrees ABOVE normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:16 and sunrise is at 6:45. Sunset is at 17:30 and twilight ends at 17:59. There's a total of 10 hours, 45 minutes of daylight today and 11 hours, 43 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 6:15 and sunrise is at 6:43. The moon is waning crescent and will be new in two days at 16:35. Illumination was 8% at midnight, will be 5% at noon and 3% at midnight tonight. Moonrise was at 5:07 this morning. Moonset was at 15:30 this afternoon. Moonrise is at 5:41 tomorrow morning. Moonlight time is 10 hours, 23 minutes which is 28 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. Presidents' Day is tomorrow. Mardi Gras is in two days. George Washington's Birthday and Ash Wednesday are in three days.