September 17: ORD

Today is September 17th. It's the 261st day of the year. 105 days remain. It's week 38 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. Observations have been official at O'Hare since Thursday, January 17, 1980.

According to the National Climatic Data Center (NCDC), the normal high is 73 and the normal low is 54. The 29-year averages are 73 and 53.

On the warm side, in 1988 the high was 90 with a low of 67. Other warm highs were 82 (1997, 2003 and two years ago) and 80 (2000, last year). The other warm lows were 66 in 1992 and 64 in 1987. The record high of 93 was set in 1955 and the record warmest low of 71 was set in 1906. 22 of the 29 highs have been 60s (9) and 70s (13). There were also five highs in the 80s and one each in the 50s and 90s.

On the cool side, in 1981 the record coolest high of 51 occurred (the only 50s high so far) with a low of 46 (just a five degree difference with the high). In 1984 the high was 69 with the record low of 37 (a 32 degree spread between the high and low). In 1980 the high was 62 with a low of 45. Other 40s lows were 44 (1983, 1995), 47 in 1999 and 48 in 1990. 19 of the last 29 lows have been in the 50s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:08 and sunrise is at 6:36. Sunset is at 18:59 and twilight ends at 19:27. Twilight begins tomorrow at 6:09 and sunrise is at 6:37. There's a total of 12 hours, 23 minutes of daylight today and 13 hours, 19 minutes between twilights. The moon reached full Harvest Monday at 4:13. Illumination was 96% at midnight, will be 93% at noon and 90% at midnight tonight. Moonset is at 9:16 this morning. Moonrise is at 19:49 tonight and moonset is at 10:33 tomorrow. Moonlight time is 13 hours, 27 minutes today.

Constitution Day, also known as Citizenship day, is today. This is a newer holiday, having been enacted by Congress just four years ago. The website "www.patriotism.org" says that Constitution Day is "a birthday for our country and it serves as a means for American citizens to express their pride in their citizenship. Constitution Day also designates a time to honor the Constitution of America and learn more about the famous piece of legislation." -Bernie-