April 30: ORD

Today is April 30th. It's the 120th day of the year. 245 days remain. It's week 18 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 64 and the normal low is 42. I've calculated the 31-year averages at 62 and 43.

On the warm side, in 2001 the high was 85 with a low of 50, a 35 degree spread. Other warm lows were 57 in 1986 and 54 last year. The record high of 91 and record warmest low of 68 were set on the same day in 1942. 26 of the last 31 highs were: 50s (10) and 60s (16). On the warmer side, three highs were: 70s (2) and 80s (1). On the cooler side, two highs were in the 40s.

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 cold 48 with a low of 35, a cold day. In 1977 the high was 71 with a low of 39, a 32 degree spread. In 1970 the high was 71 with a low of 66, a five degree spread and warm day. In 1968 the high was 72 with a low of 42, a 30 degree spread. In 1964 the high was a cold 49 with a low of 45, a four degree spread. In 1963 the high was a cold 51. In 1962 the high was a warm 84 with a low of 49, a 35 degree spread and warm day. In 1961 the high was 67 with a low of 36, a 31 degree spread.

More recently, we had a small spread of seven degrees three years ago (59/52). The large spreads were 35 degrees in 1985 (75/40), 34 degrees in 2000 (71/37) and 31 degrees in 1988 (69/38).

On the cool side, in 1994 the high was 43 with a low of 34. In 1979 the high was 47 with a low of 35. Other cool highs were 50 in 1995 and 52 a year later in 1996. The record low of 30 occurred way back in 1873. Two years ago the low was a near-record 31 degrees. The record coldest high of 39 was set way back in 1907. 24 of the last 31 lows were: 30s (12) and 40s (12). Seven lows were in the warmer 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:20 and sunrise was at 5:50. Sunset is at 19:52 and twilight ends at 20:22. There's a total of 14 hours, 2 minutes of daylight today and 15 hours, 2 minutes between twilights. Tomorrow twilight begins at 5:18 and sunrise is at 5:49. The moon is waning gibbous, having reached the full Pink moon two days ago at 7:18. Illumination was 96% at midnight, will be 94% at noon and 91% at midnight tonight. Moonset was at 6:53 this morning. Moonrise is at 22:47. Moonset is at 7:45 tomorrow morning. Moonlight time is 8 hours, 6 minutes which is 18 minutes shorter than yesterday.

National Teacher Day is in five days. Mother's Day is in nine days. - Bernie -