May 6: ORD

Today is May 6th. It's the 126th day of the year. 239 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 67 and the normal low is 44. I've calculated the 31-year averages at 70 and 46.

On the warm side, in 2000 the high was 86 with a low of 62. In 1986 the high was 84 with a low of 63. In 2004 the high was 83 with a low of 55. In 1982 the high was 82 with a low of 54. In 1998 the high was 77 with a low of 58. In 2002 the high was 75 with a low of 60. Two years ago the high was 81. The other upper 70s highs were 78 in 1993, 77 in 1988 and 77 in 1983. The record high of 91 was set in 1949 and the record warmest low of 66 was set in 1965. 14 of the last 31 highs were 70s. On the warmer side, five highs were 80s. 12 highs were in the cooler: 40s (2), 50s (5) and 60s (5).

In looking back through the years to the first May at O'Hare in 1959, the following instances were notable: in 1976 the high was a cold 43 with a low of 35, a cold day. In 1975 the high was a cold 52. In 1974 the high was a cold 51 with a low of 36, a cold day. In 1970 the high was a cold 51 with a low of 34, a cold day. In 1969 the high was 78 with a warm low of 63, a warm day. In 1968 the high was 61 with a cold low of 31, a 30 degree spread. In 1967 the high was a cold 53. In 1966 the high was 70 with a low of 40, a 30 degree spread. In 1965 the high was 77 with a warm low of just 66, a warm day. 1965 was the year of the record warmest low, also 66 at Midway. In 1964 the high was 77 with a warm low of just 65, a warm day. In 1963 the high was 69 with a low of 38, a 31 degree spread. In 1959 the high was a warm 85 with a low of 53, a 32 degree spread and warm day.

More recently, we had a small spread of six degrees in 1991 (48/42). The large spreads were 36 degrees in 1987 (76/40), 35 degrees last year (81/46), 33 degrees in 1993 (78/45), 33 degrees in 1995 (72/39), 32 degrees in 1980 (73/41), 32 degrees in 1988 (77/45) and 31 degrees in 1983 (77/46).

On the cool side, in 1989 we had our record coldest high of 42 with a near-record low of 31. The record low of 30 was set in 1992. In 1981 the high was 50 with a low of 36. Other cool highs were 48 in 1991, 53 in 1996 and 54 in 1994. 14 of the last 31 lows were 40s. Six lows were in the colder 30s. 11 lows were in the warmer: 50s (8) and 60s (3).

Today is a major day in Chicago's snow history. Twenty-one years ago (1989) we had half an inch of snow at O'Hare. Rockford had but a trace. But this was not the last event. Stay tuned, for in five days we had another event!

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:11 and sunrise was at 5:42. Sunset is at 19:58 and twilight ends at 20:29. There's a total of 14 hours, 16 minutes of daylight today and 15 hours, 18 minutes between twilights. Tomorrow twilight begins at 5:10 and sunrise is at 5:41. The moon reached last quarter last night at 23:15 and is waning crescent. Illumination was 49% at midnight, will be 45% at noon and 40% at midnight tonight. Moonrise was at 2:00 early this morning. Moonset is at 12:48. Moonrise is at 2:24 early tomorrow morning. Moonlight time is 10 hours, 48 minutes which is 35 minutes longer than yesterday.

Mother's Day is in three days. - Bernie -