March 22: ORD

Today is March 22nd. It's the 82nd day of the year. 284 days remain. It's week 12 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. ORD has been the official site of record for Chicago since Thursday, January 17, 1980. Before this, the official site of record 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 49 and the normal low is 31. I've calculated the 32-year averages at 49 and 30.

On the warm side, in 1991 (until 2012, O'Hare's warmest March 22nd) the high was 64 with a low of 46 (O'Hare's warmest low of the date until 2012). Three years later, in 1994, the high was 71 (O'Hare's only 70s high of the date and warmest high of the date until 2012) with a low of 37, a 34 degree spread. In 2007 the high was 64 with a low of 44. The other warm highs were 69 in 1979, 64 in 1988 and 61 three years ago in 2009. The other warm low was 43 in 2000. The record high of 79 and the record warmest low of 59 were set on the same warm day back in 1938, at a time when the official readings were taken adjacent to Lake Michigan. 15 of the past 33 highs (46%) were in the 40s. On the warm side, 12 highs (36%) were in the: 50s (5), 60s (6) and 70s (1). Our most recent 50s high was 56 in 2001. Prior to 1979, O'Hare's warmest high was 60 in 1969. On the cold side, six highs (18%) were in the: 20s (1) and 30s (5).

In looking back through the years to the first March at O'Hare in 1959, the following instances were notable: In 1969 the high was 60 with a low of 26, a 34 degree spread. In 1968 the high was a cold 33 with a low of 26, a seven degree spread. In 1965 the high was a cold 35 with a low of 21, a cold day. In 1962 the high was 38 with a low of 33, a five degree spread. In 1961 the high was 45 with a low of 38, a seven degree spread. In 1960 the high was 35 with a low of 17, cold day. In 1959 the low was a cold 18 degrees.

More recently, we had a small spread of five degrees in 1993 (38/33) and five degrees last year, in 2011 (42/37). There were large spreads of 38 degrees in 1979 (69/31) and 35 degrees in 1988 (64/29).

On the cold side, in 1983 (O'Hare's coldest March 22nd) the high was 28 (O'Hare's only 20s high of the date) with a low of 13. In 2002 the high was 37 with a low of 14. In 1992 the high was 34 with a low of 20. The other cold low was 19 in 2004. The other cold highs were 36 in 1984 and 37 in 2008. The record low of -1 and record coldest high of 18 were set on the same cold day way back in 1888, at a time when the official readings were taken adjacent to Lake Michigan. 27 of the last 33 lows (82%) were in the: 20s (14) and 30s (13). Three lows were in the cold 10s (a.k.a. teens). O'Hare's cold lows, prior to 1979, are 17 in 1960 and 18 in 1959. Three lows were in the warm 40s.

There was an instance of back-to-back years in which temperatures were just about as opposite as they can be. In 1991 the high was 64 with a low of 46, overall 15 degrees ABOVE normal. Then in 1992 the high was 34 with a low of 20, overall 13 degrees BELOW normal.

Today is a major day in Chicago's snow history. At O'Hare in 1965, this was the third of seven days in which a total of 10.2 inches fell. Today 3.5 inches fell. In 1932 in Rockford, 4 inches fell following 11 inches the previous day. Four years ago, in 2008, this was the second day of a two day storm. At O'Hare, 0.6 inches fell, part of a 5.4 inch total. Rockford had 0.3 inches, part of a 5.6 inch total. Midway had 0.4 inches, part of a 3 inch total. Midway's total was held down because part of it was a wintry mix (freezing rain, sleet).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:24 and sunrise is at 6:52. Sunset is at 19:08 and twilight ends at 19:36. There's a total of 12 hours, 16 minutes of daylight today and 13 hours, 12 minutes between twilights. We gained three minutes of daylight from yesterday. Tomorrow twilight begins at 6:23 and sunrise is at 6:51. The moon is waning crescent and will be new this morning at 9:37. Illumination was 0% at midnight, will be 0% at noon and 1% at midnight tonight. Moonrise is at 6:31 this morning. Moonset is at 19:35 tonight. Moonrise is at 6:57 tomorrow morning. Moonlight time is 13 hours, 4 minutes which is 35 minutes longer than yesterday.

Spring began on March 12th and runs for 84 days through June 3rd. Cool Spring began on March 12th and runs for 32 days through April 12th. High temperatures in this period are usually in the 30s, 40s and 50s. Highs in the 60s and 70s usually occur infrequently. April Fools' Day and Palm Sunday are in ten days.