April 11: ORD

Today is April 11th. It's the 101st day of the year. 264 days remain. It's week 15 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 56 and the normal low is 36. I've calculated the 31-year averages at 56 and 37.

On the warm side, in 2005 the high was 76 with a low of 53. Four years before, in 2001, the high was 77 with a low of 51. Five years before, in 1996, the high was 82 with a low of 45, a 37 degree spread. In 2002 the high was 75 with a low of 50. Four years later, in 2006, the high was 75 with a low of 48. Other warm highs were 70 in 2003 and 69 in 1981. The record high of 90 was set back in 1930. The record warmest low of 60 was set in 1977. 11 of the last 31 highs were 40s. On the warmer side, 18 highs were: 50s (6), 60s (6), 70s (5) and 80s (1). On the colder side, two highs were 30s.

In looking back through the years to the first April at O'Hare in 1959, the following instances were notable: In 1977 the high was 84 with a low of 59, a warm day and year of the record warmest low. In 1976 the high was a cold 41. In 1974 the high was 65 with a warm low of 50. In 1971 the high was a warm 80 with a low of 47, a 33 degree spread and warm day. In 1968 the high was a warm 74 with a low of 39, a 35 degree spread. In 1965 the high was 75 with a low of 49, a warm day. In 1964 the high was a warm 76 with a low of 41, a 35 degree spread and warm day. In 1959 the high was a cold 44.

More recently, we had large spreads of 32 degrees in 1998 (66/34), 35 degrees in 1986 (66/31) and 38 degrees in 2003 (70/32). There were no small spreads other than in 1997 (see next section).

On the cold side, in 1997 the high was 35 with a low of 32, a three degree spread. In 2000 the high was 39 with a low of 29. Another cold low was the record low of 25 in 1989. Other cold highs were 40 in 1990, 43 in 2004, 43 three years ago and 44 in 1991. The record coldest high of 33 was set way back in 1882. 16 of the last 31 lows were 30s. Four lows were in the colder 20s. 11 lows were in the warmer: 40s (8) and 50s (3).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:50 and sunrise was at 6:19. Sunset is at 19:30 and twilight ends at 19:59. There's a total of 13 hours, 11 minutes of daylight today and 14 hours, 9 minutes between twilights. Tomorrow twilight begins at 5:49 and sunrise is at 6:17. The moon is waning crescent. Illumination was 10% at midnight, will be 8% at noon and 5% at midnight tonight. Moonrise was at 4:43 this morning. Moonset is at 17:00. Moonrise is at 5:04 tomorrow morning. Moonlight time is 12 hours, 17 minutes which is 38 minutes longer than yesterday.

Illinois Tax Freedom Day is today. - Bernie -