May 7: ORD

Today is May 7th. It's the 127th day of the year. 238 days remain. It's week 19 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 32-year averages at 67 and 46.

On the warm side, in 2000 the high was 77 with a low of 64. In 1979 the high was 81 with a low of 57. In 1993 the high was 78 with a low of 55. Two years ago, in 2009, the high was 77 with a low of 56. Other 80s highs were 84 in 1988 and 83 in 2007. Other mid 70s highs were 75 in 1990, 75 in 1995 and 73 in 1985. The record high of 87 was set in 1964 and the record warmest low of 68 occurred way back in 1880. 29 of the last 32 highs (91%) were in the: 50s (10), 60s (8) and 70s (11). On the warmer side, three highs were in the 80s.

In looking back through the years to the first May at O'Hare in 1959, the following instances were notable: in 1978 the high was a cool 53 and in 1977 the high was a cool 54. In 1976 the high was a cool 52 with a low of 33, a cold day. In 1974 the high was 54 with a low of 32, a cold day. In 1973 the high was 60 with a low of 53, a seven degree spread. In 1972 the high was a cold 47 with a low of 42, a five degree spread. In 1970 the high was 78 with a low of 38, a 40 degree spread. In 1969 the high was 76 with a warm low of 58, a warm day. In 1966 the high was 73 with a low of 35, a 38 degree spread. In 1965 the high was 83 with a low of 61, a warm day. In 1964 the high was 85 with a low of 61, the year of the record high (87 at Midway) and a warm day. In 1963 the high was a warm 81 with a low of 49, a 32 degree spread. In 1960 the high was a cool 51 with a low of 36, a cold day.

More recently, we had small spreads of four degrees in 1998 (59/55) and five degrees in 1999 (58/53). The large spreads were 44 degrees in 1988 (84/40), 37 degrees in 1992 (71/34), 36 degrees in 2007 (83/47), 35 degrees in 1985 (73/38) and 34 degrees in 2006 (71/37).

On the cool side, in 1989 the high was 57 with the record low of 29. In 1981 the high was 59 with a low of 32. Other cool highs were 53 in 1994 and 55 in 2004. The record coldest high of 43 occurred back in 1931. 24 of the last 32 lows (75%) were in the: 40s (15) and 50s (9). Seven lows were in the cold: 20s (1) and 30s (6). One low was in the warm 60s.

Where the most recent days stand over the past 33 years: Thu. 4/28: second coldest; Fri. 4/29: seventh coldest; Sat. 4/30: fourth warmest; Sun. 5/1: slightly above normal; Mon. 5/2: a bit below normal; Tue. 5/3: third coldest; Wed. 5/4: fifth coldest; Thu. 5/5: fourth coldest; Fri. 5/6: slightly above normal.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight is at 5:10 and sunrise is at 5:42. Sunset is at 19:59 and twilight ends at 20:30. There's a total of 14 hours, 17 minutes of daylight today and 15 hours, 20 minutes between twilights. We gained two minutes of daylight from yesterday. Tomorrow twilight begins at 5:09 and sunrise is at 5:40. The moon is waxing crescent and will reach first quarter in three days at 15:33. Illumination was 15% at midnight, will be 19% at noon and 23% at midnight tonight. Moonrise is at 8:53 this morning. Moonset is at 0:12 tomorrow morning. Moonrise is at 9:58 tomorrow morning. Moonlight time is 15 hours, 7 minutes which is 27 minutes shorter than yesterday.

The warm part of Spring (Warm Spring) began on April 13. Warm Spring runs for 52 days, through June 3. High temperatures in this period are usually in the 50s, 60s and 70s. Warmer 80s and 90s occur infrequently. Mother's Day is tomorrow. Armed Forces Day is in 14 days. -Bernie-