April 12: ORD

Today is April 12th. It's the 102nd day of the year. 263 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 57 and the normal low is 36. I've calculated the 31-year averages at 55 and 37.

On the warm side, in 2006 the high was 76 with a low of 58. In 1998 the high was 73 with a low of 55. In 1979 the high was 77 with a low of 45, a 32 degree spread. Six years later, in 1985, the high was 76 with a low of 43, a 33 degree spread. The record high of 86 and record warmest low of 60 were set on the same day in 1977. The record high of 86 also occurred in 1971. 21 of the last 31 highs were: 40s (9) and 50s (12). On the warmer side, eight highs were: 60s (4) and 70s (4). 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 83 with a low of 57, a warm day, year of the record high and record warmest low. In 1974 the high was 73 with a low of 53, a warm day. In 1971 the high was a warm 85 with a low of 45, a 40 degree spread and warm day. In 1968 the high was 81 with a low of 54, a warm day. In 1964 the low was a warm 51. In 1963 the high was 61 with a low of 26, a 35 degree spread. In 1962 the high was a cold 45. In 1961 the high was 44 with a low of 37, a seven degree spread. In 1960 the high was a warm 72 with a low of 42, a 30 degree spread.

More recently, we had small spreads of five degrees two years ago (38/33) and seven degrees in 1981 (50/43).

On the cold side, in 1997 the high was 36 with a low of 30, a six degree spread. Other cold highs were 38 three years ago, 41 in 1992, 42 in 2004, 42 two years ago, 44 in 1995 and 45 in 1990. The record low of 21 was set back in 1939 and again in 1957. The record coldest high of 34 was set in 1950. 25 of the last 31 lows were: 30s (16) and 40s (9). Four lows were in the colder 20s. Two lows were in the warmer 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:49 and sunrise was at 6:17. Sunset is at 19:31 and twilight ends at 20:00. There's a total of 13 hours, 14 minutes of daylight today and 14 hours, 11 minutes between twilights. Tomorrow twilight begins at 5:47 and sunrise is at 6:16. The moon is waning crescent, heading towards new in two days. Illumination was 5% at midnight, will be 3% at noon and 2% at midnight tonight. Moonrise was at 5:04 this morning. Moonset is at 18:02. Moonrise is at 5:27 tomorrow morning. Moonlight time is 12 hours, 58 minutes which is 41 minutes longer than yesterday.

A niece of mine, Sara, celebrates a birthday in four days. - Bernie -