Tuesday, July 28, 2009

July 26: ORD

Today is July 26th. It's the 207th day of the year. 158 days remain. It's week 30 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 84 and the normal low is 64. I've calculated the 30-year averages at 83 and 65.


On the hot side, there were no days of a mean of at least 11.5 degrees above normal. In 1997 the high was 97 with a low of 73. Another warm low was 73 in 1982.
The record high of 99 was set in 1955. The record warmest low of 80 occurred back in 1916. 20 of the last 30 highs were 80s. Three highs were in the warmer 90s. Seven highs were in the cooler: 60s (1) and 70s (6). There have been two periods of sub 90 degree weather. The first of these was nine years from 1988 to 1996 and the second is still ongoing, 12 years from 1998 through 2009.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 19
72 the high was 70 with a low of 63, a mere seven degree spread. In 1966 the high was 93. In 1962 the low was a very cool 49.

More recently, there w
as a small spread of five degrees in 1981 (71/66).

On the cool side, in 1984 the high was 67 with a low of 55. Another cool high was 71 in 1981. The record low of 53 was set in 1962 and tied in 1991. The record coolest high of 66 occurred way back in 1891. 16 of the last 30 lows were 60s. Seven lows were in the cooler 50s. Seven lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:08 and sunrise is at 5:40. Sunset is at 20:19 and twilight ends at 20:51. Tomorrow twilight begins at 5:09 and sunrise is at 5:41. There's a total of 14 hours, 39 minutes of daylight today and 15 hours, 43 minutes between twilights. The moon is waxing crescent. Illumination was 23% at midnight, will be 28% at noon and 33% at midnight tonight. Moonrise is at 11:17 this morning. Moonset is at 22:36 tonight. Moonrise is at 12:27 tomorrow morning. Moonlight time is 11 hours, 19 minutes which is 48 minutes shorter than yesterday.

Parent's Day is today. -Bernie-

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