Sunday, September 13, 2009

September 13: ORD

Today is September 13th. It's the 256th day of the year. 109 days remain. It's week 37 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 75 and the normal low is 55. I've calculated the 30-year averages at 77 and 58.


On the hot side, in 2005 the high was 94 with a low of 71. In 1994 the high was 88 with a low of 66. Another warm high was 90 in 1998. Other warm lows were 70 in 1982, 68 (1993, 2003 and last year) and 67 in 1980. The record high of 98 was set back in 1939. The record warmest low of 75 occurred back in 1927,
a time when the official readings were taken on the lakefront. Over the last 30 years, 21 highs were: 70s (11) and 80s (10). Two highs were in the warmer 90s. Seven highs were in the cooler 60s.

In looking back through the years to the first September at O'Hare in 1959, the following instances were notable: in 1978 the high was 86 with a low of 67, a hot day. In 1975 the high was 63 with a low of 40, a cool day. In 1974 the high was 59 with a low of 44, a cool day. In 1970 the high was 59 with a low of 52, a seven degree spread. In 1964 the high was 70 with a low of 37, a 33 degree spread and cool day. That low of 37 was cooler than the record low.
In 1963 the high was 62 with a low of 43, a cool day. In 1962 the high was 91 with a low of 71, a hot day.

More recently, there w
ere large spreads of 33 degrees in 1998 (90/57) and 32 degrees in 2000 (79/47). There were small spreads of five degrees in 2006 (65/60), seven degrees in 1989 (60/53) and seven degrees last year (75/68). Last year we were getting lots of rain from the remnants of Hurricane Ike. O'Hare recorded 6.64 inches of rain.

On the cool side, in 1985 the high was 64 with a low of 42. Other cold lows were the four others in the 40s, the coolest of these was 47 degrees, occurring in 2000. Three lows were 48 degrees. The record low of 39 was set way back in 1890. Other cool highs were the coolest reading of 60 in 1989 and another high of 64 in 1996. The record coolest high of 55 occurred way back in 1880, a time when the official readings were taken on the lakefront. Over the last 30 years, 23 lows were: 50s (11) and 60s (12). Five lows were in the cooler 40s. Two lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 6:03 and sunrise is at 6:31. Sunset is at 19:06 and twilight ends at 19:34. Tomorrow twilight begins at 6:04 and sunrise is at 6:32. There's a total of 12 hours, 35 minutes of daylight today (three minutes less than yesterday) and 13 hours, 31 minutes between twilights. The moon is waning crescent, having reached last quarter two nights ago at 21:16. Illumination was 37% at midnight, will be 32% at noon and 26% at midnight tonight. Moonrise was at six minutes past midnight. Moonset is at 15:59 this afternoon. Moonrise is at 1:19 early tomorrow morning. Moonlight time is 15 hours, 53 minutes which is 44 minutes longer than yesterday.

My oldest sister, Mary Ann, and her husband, William, celebrate their 7th wedding anniversary today. Grandparent's Day is also today. Maria, my second youngest sister, and her husband, Buddy, celebrate their 8th wedding anniversary tomorrow. Citizenship Day is in four days. The autumnal equinox is in nine days. -Bernie-

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