October 2: ORD

Today is October 2nd. It's the 275th day of the year. 90 days remain. It's week 40 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 48. I've calculated the 31-year averages at 69 and 46.

On the warm side, in 1991 the high was 80 with a low of 59. Other warm highs were 88 in 1983, 84 in 2005, 81 in 1982 and 81 in 2000. Other warm lows were 61 in 2006, 60 in 1986 and 60 in 2002. In 1971 the record high of 91 and record warmest low of 69 were established at Midway. Over the last 31 years, the four categories of highs have been almost equal: 50s (8), 60s (10), 70s (7) and 80s (6). Interestingly, although the 60s are most represented, only one 60 degree high has occurred in the last 13 years. This was 61 two years ago in 2008. Of the 12 other highs, five have been 50s, four have been 70s and three have been 80s. The 60s were most in vogue from 1984 to 1989 when five of those six years had one.

In looking back through the years to the first October at O'Hare in 1959, the following instances were notable: in 1976 the high was 80 with a low of 49, a 31 degree spread. In 1975 the high was a cool 57 degrees. In 1974 the high was 50 with a low of 27, a cool day. That low of 27 was cooler than the record low of 28 which was set this same year at Midway. In 1972 the high was 78 with a low of 46, a 32 degree spread. In 1971 the high was 89 with a low of 69, a hot day. 1971 was the year of the record high of 91 and record warmest low of 69, both set at Midway. In 1967 the high was 84 with a low of 61, a hot day. In 1966 the high was 69 with a cool low of 33 degrees, a 36 degree spread. In 1963 the high was a warm 82 degrees. In 1962 the low was a warm 60. In 1961 the high was 52 with a low of 30, a cool day.

More recently, there were large spreads of 39 degrees in 1983 (88/49), 37 degrees in 1997 (79/42), 34 degrees in 1990 (73/39), 32 degrees in 1982 (81/49), 32 degrees in 2001 (80/48), 31 degrees in 1984 (68/37), 30 degrees in 1992 (78/48) and 30 degrees in 2005 (84/54). There was a small spread of seven degrees in 1986 (67/60).

On the cool side, in 2003 the high was 53 with a low of 31. In 1981 the high was 52 with a low of 32. In 1993 the high was 55 with a low of 33. In 1999 the high was 55 with a low of 36. In 1987 the high was 58 with a low of 33. Another cool low was 34 in 1985. Other cool highs were 56 last year and 57 in 1998. The record low of 28 was set in 1974 and the record coolest high of 48 was set way back in 1888, a time when the official readings were taken adjacent to Lake Michigan. 28 of the last 31 lows (90%) were: 30s (9), 40s (12) and 50s (7). Three lows were in the warmer 60s. The tallies of lows over the last eight years has been an even mix: two 30s, two 40s, two 50s and two 60s. There was a 15 year absence of a low in the 60s between the low of 60 in 1986 to the low, also 60, in 2002.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:23 and sunrise is at 6:51. Sunset is at 18:33 and twilight ends at 19:01. There's a total of 11 hours, 42 minutes of daylight today and 12 hours, 38 minutes between twilights. We are losing two or three minutes of daylight a day. Tomorrow twilight begins at 6:25 and sunrise is at 6:53. The moon reached last quarter two nights ago at 22:52 and is waning crescent. Illumination was 38% at midnight, will be 33% at noon and 27% at midnight tonight. Moonrise is at 29 minutes past midnight. Moonset is at 15:27 this afternoon. Moonrise is at 1:43 tomorrow morning. Moonlight time is 14 hours, 58 minutes which is 11 minutes longer than yesterday.

Columbus Day is in nine days. -Bernie-