September 28: ORD

Today is September 28th. It's the 271st day of the year. 94 days remain. It's week 39 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 69 and the normal low is 49. I've calculated the 31-year averages at 69 and 49.

On the warm side, in 1986 the high was 82 with the only 60s low of 65. Other warm highs were 83 in 1979, 82 in 1987, 81 in 1983 and 81 in 1995. The last 80s high was 15 years ago in 1995. The record high of 92 was set in 1953 and the record warmest low of 71 occurred in 1971. Over the last 31 years, 12 highs have been 60s. 13 highs were in the warmer: 70s (8) and 80s (5). Six highs were in the cooler 50s.

In looking back through the years to the first September at O'Hare in 1959, the following instances were notable: in 1975 the high was 73 with a low of 40, a 33 degree spread. In 1973 the low was a warm 64 degrees. In 1971 the high was 89 with a low of 73, a hot day and year of the record warmest low. In 1967 the high was a cool 53 with a low of 41, a cool day. In 1964 the high was 62 with a cold low of 32, a 30 degree spread and cool day. In 1963 the high was a hot 87 with a low of 53, a 34 degree spread. In 1961 the high was 56 with a low of 33, a cool day. In 1959 the high was 77 with a warm low of 64, a warm day.

More recently, there were large spreads of 32 degrees in 1979 (83/51), 32 degrees in 1989 (74/42) and 31 degrees in 1985 (76/45). There were small spreads of four degrees in 2001 (56/52) and seven degrees in 1988 (65/58).

On the cool side, in 1984 the high was 56 with a low of 36. Another cool high was 56 in 2001. Another cool low was 36 in 1991. The record low of 29 was set in 1942. The record coolest high of 50 was set way back in 1893. 27 of the last 31 lows (87%) were: 40s (11) and 50s (16). Three lows were in the cooler 30s and one was in the warmer 60s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:19 and sunrise is at 6:47. Sunset is at 18:40 and twilight ends at 19:08. There's a total of 11 hours, 53 minutes of daylight today and 12 hours, 49 minutes between twilights. We are losing two or three minutes of daylight a day. Tomorrow twilight begins at 6:20 and sunrise is at 6:48. The moon is waning gibbous. Illumination was 79% at midnight, will be 74% at noon and 70% at midnight tonight. Moonset is at 12:12 this afternoon. Moonrise is at 21:22 tonight. Moonset is at 13:10 tomorrow afternoon. Moonlight time is 14 hours, 50 minutes which is 16 minutes longer than yesterday.

Columbus Day is in 13 days. -Bernie-