October 15: ORD

Today is October 15th. It's the 288th day of the year. 77 days remain. It's week 42 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 63 and the normal low is 42. I've calculated the 31-year averages at 63 and 44.

On the warm side, in 1989 the high was 83 (our only 80s high) with a low of 60. A year earlier, in 1988, the high was 76 with a low of 55. Other warm highs were 79 in 1999, 78 in 1996 and 75 in 1987. Another warm low was 54 in 1984. The record high of 88 was set in 1947 and the record warmest low of 69 occurred way back in 1897. Over the last 31 years, 28 highs (90%) have been: 50s (8), 60s (12) and 70s (8). One high was in the warmer 80s and two highs were in the cooler 40s.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1978 the high was 52 with a low of 31, a cool day. In 1972 the high was a cool 51 with a low of 31, a cool day. In 1971 the high was a warm 77 degrees. In 1968 the high was 84 with a low of 67, a hot day. In 1965 the high was 74 with a warm low of 58, a warm day. In 1964 the high was 74 with a low of 33, a 41 degree spread. In 1963 the high was a hot 84 with a low of 35, an incredible 49 degree spread. In 1962 the high was 87 with a low of 64, a hot day. In 1961 the high was 71 with a low of 37, a 34 degree spread. In 1960 the low was a warm 54 degrees.

More recently, there were large spreads of 38 degrees in 1983 (73/35) and 31 degrees in 1999 (79/48). There were small spreads of two degrees in 1992 (51/49) and three degrees last year (44/41).

On the cool side, in 1991 the high was 49 with a low of 32. In 2006 the high was 52 with a low of 31. Other cool highs were 44 last year and 51 in 1992. The record low of 28 was set way back in 1876. The record coolest high of 44 occurred in 1943 and was tied last year. 23 of the last 31 lows (74%) were: 30s (11) and 40s (12). Eight lows were in the warmer: 50s (7) and 60s (1).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:38 and sunrise is at 7:06. Sunset is at 18:11 and twilight ends at 18:40. There's a total of 11 hours, 5 minutes of daylight today and 12 hours, 2 minutes between twilights. We are losing two or three minutes of daylight a day. Tomorrow twilight begins at 6:39 and sunrise is at 7:07. The moon reached first quarter yesterday at 16:27 and is waxing gibbous. Illumination was 54% at midnight, will be 58% at noon and 63% at midnight tonight. Moonrise is at 14:40 this afternoon. Moonset is at 0:53 tomorrow morning. Moonrise is at 15:08 tomorrow afternoon. Moonlight time is 9 hours, 20 minutes which is 23 minutes shorter than yesterday.

United Nation's Day is in nine days. Halloween is in 16 days. Election Day is in 18 days. -Bernie-