April 1: ORD

Today is April 1st. It's the 91st day of the year. 274 days remain. It's week 13 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 53 and the normal low is 33. I've calculated the 31-year averages at 53 and 34.

On the warm side, in 2003 the high was 81 with a low of 39, a 42 degree spread. That high of 81 was just a degree short of the record. Four years earlier, in 1999, the high was 62 with a low of 53. That low of 53 was just a degree short of the record warmest low. Other warm highs were 67 in both 1986 and 1994. Other warm lows were 46 two years ago and 47 in 2000. The record high of 82 was set in 1946 and the record warmest low of 54 was set in 1963. 21 of the last 31 highs were: 40s (10) and 50s (11). On the warmer side, seven highs were: 60s (6) and 80s (1). There have been no highs in the 70s. On the colder side, three highs were 30s.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1978 the high was a warm 67 with a low of 32, a 35 degree spread. In 1976 the high was 43 with a low of 37, a six degree spread. In 1974 the high was a warm 71 with a low of 41, a 30 degree spread and warm day. In 1972 the high was a cool 38. In 1970 the high was a cool 36 with a low of 34, a two degree spread. In 1969 the high was 64 with a low of 33, a 31 degree spread. In 1964 the low was a cold 19. In 1963 the high was 77 with a low of 54, a warm day and year of the record warmest low. In 1962 the high was a cold 40. In 1961 the high was a cold 37 with a low of 22, a cold day. In 1959 the high was 42 with a low of 38, a four degree spread.

More recently, we had a small spread of five degrees in 1979 (39/34). There were large spreads of 35 degrees in 1997 (62/27), 30 degrees in 1986 (67/37), 30 degrees in 1994 (67/37) and 31 degrees in 1984 (55/24).

On the cold side, in 1993 the high was 35 with a low of 27. Other cold highs were 39 in 1979, 39 in 1992, 41 in 1985 and 41 in 2002. The record low of 17 and record coldest high of 26 were set on the same day way back in 1881. 17 of the last 31 lows were 30s. Eight lows were in the colder 20s. Six lows were in the warmer: 40s (5) and 50s (1).

Today is a major day in Chicago's snow history. 1970 was the first day of a two day storm. At O'Hare, 3.2 inches of a 7.2 inch total occurred. At Midway, 8.2 inches of a 10.7 inch total occurred. And in Rockford, 3.9 inches of a 6.7 inch total occurred.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 6:08 and sunrise was at 6:36. Sunset is at 19:19 and twilight ends at 19:47. There's a total of 12 hours, 43 minutes of daylight today and 13 hours, 39 minutes between twilights. Tomorrow twilight begins at 6:06 and sunrise is at 6:34. The moon is waning gibbous. Illumination was 94% at midnight, 91% at noon and 87% at midnight tonight. Moonset was at 7:35. Moonrise is at 22:57. Moonset is at 8:16 tomorrow morning. Moonlight time is 8 hours, 38 minutes which is 36 minutes shorter than yesterday.

April Fool's Day is today. Good Friday is tomorrow. Easter is in three days. -Bernie-