April 24: ORD

Today is April 24th. It's the 114th day of the year. 251 days remain. It's week 17 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.

According to the National Climatic Data Center (NCDC), the normal high is 61 and the normal low is 40. I've calculated the 32-year averages at 64 and 42.

On the warm side, in 1990 the high was the record high of 87 with a low of 66. Four years later, in 1994, the high was 83 with a low of 54. Two years ago, in 2009, the high was 84 with a low of 49, a 35 degree spread. In 1986 the high was 81 with a low of 47, a 34 degree spread. In 1993 the high was 76 with a low of 52. Three years ago, in 2008, the high was 74 with a low of 54. Other warm highs were 75 in 1998, 73 in 1982, 73 in 2002 and 73 in 2006. Another warm low was 55 in 1979. The record warmest low of 68 was set in 1915. The record high of 87 originally occurred in 1915, making 1915 the overall warmest day. 26 of the last 32 highs were in the: 50s (9), 60s (10) and 70s (7). Our most recent 50s high was 54 in 2005. On the warmer side, four highs were in the 80s. On the cold side, two highs were in the 40s (44 in 1980 and 48 in 1992). The past five years produced two 60s highs, two 70s highs and one 80s high.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1972 the high was a cold 45 with a low of 34, a cold day. In 1968 the high was a cold 41 with a low of 36, a five degree spread and cold day. In 1967 the high was 40 with a low of 25, a cold day. In 1965 the high was a cold 45 with a low of 40, a five degree spread. In 1962 the high was a warm 78 with a low of 44, a 34 degree spread. In 1961 the high was a warm 76 with a low of 40, a 36 degree spread. In 1960 the high was 85 with a low of 65, a hot day.

More recently, we had large spreads of 34 degrees in 2006 (73/39), 32 degrees in 1996 (68/36), 31 degrees in 2002 (73/42) and 30 degrees in 1995 (62/32).

On the cold side, in 1980 the high was 44 with a low of 32. In 1983 the high was 54 with a low of 32. Another cold high was 48 in 1992. The record low of 29 was set way back in 1910. The record coldest high of 36 was set way back in 1892. 26 of the last 32 lows (81%) were in the: 30s (14) and 40s (12). Six lows were in the warmer: 50s (5) and 60s (1).

The recent cold of April 2011: Monday, April 18: high of 41, low of 32. The second coldest April 18 of the past 33 years. Only 1983 (37/23) was colder. Tuesday, April 19: high of 38, low of 34. The second coldest April 19 of the past 33 years. Only 1983 (44/22) was colder. Wednesday, April 20: high of 43, low of 32. The second coldest April 20 of the past 33 years. Only 1981 (41/30) was colder.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:29 and sunrise was at 5:59. Sunset is at 19:45 and twilight ends at 20:15. There's a total of 13 hours, 46 minutes of daylight today and 14 hours, 46 minutes between twilights. We gained four minutes of daylight from yesterday. Tomorrow twilight begins at 5:28 and sunrise is at 5:58. The moon reaches last quarter tonight at 21:47. Illumination was 59% at midnight, will be 54% at noon and 49% at midnight tonight. Moonrise was at 1:40 this morning. Moonset was at 11:40 this morning. Moonrise is at 2:13 tomorrow morning. Moonlight time is 10 hours which is 25 minutes longer than yesterday.

The warm part of Spring (Warm Spring) began on April 13. Warm Spring runs for 52 days, through June 3. High temperatures in this period are usually in the 50s, 60s and 70s. Warmer 80s and 90s occur infrequently. Easter is today. Administrative Professionals Day is in three days. Arbor Day is in five days. -Bernie-