Wednesday, August 26, 2009

August 26: ORD

Today is August 26th. It's the 238th day of the year. 127 days remain. It's week 34 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 79 and the normal low is 60. I've calculated the 30-year averages at 83 and 64.


On the hot side, in 1993 the high was 94 with a low of 74. A decade later, in 2003, the high was 92 with a low of 71. The other 90s highs were 93 in 1991, 92 in 1980 and 91 in 1995. The only other 70s low was 70 in 1990. The record high of 97 and record warmest low of 77 were set on the same day in 1973.
Over the last 30 years, 16 highs were 80s. Five highs were in the warmer 90s. Nine highs were in the cooler: 70s (8) and 60s (1).

In looking back through the years to the first August at O'Hare in 1959, the following instances were notable: In 1973 the high was 93 with a low of 75, a hot day. This was the year that the records were set at Midway Airport. In 19
68 the high was just 65. In 1964 the high was 74 with a low of 41, a 33 degree spread and cool day. That low of 41 was cooler than the record low. In 1959 the high was 92 with a low of 74, a hot day.

More recently, there w
ere no small spreads of up to seven degrees or large spreads of at least 30 degrees.

On the cool side, there were no days of a mean of at least 11.5 degrees below normal. The coolest temperature was 54 degrees in 1988. The record low of 47 was set way back in 1887. The coolest high was 65 degrees in 1987. The record coolest high of 61 occurred way back in 1885. Over the last 30 years, 20 lows were in the 60s. Seven lows were in the cooler 50s. Three lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight is at 5:43 and sunrise is at 6:13. Sunset is at 19:37 and twilight ends at 20:06. Tomorrow twilight begins at 5:44 and sunrise is at 6:14. There's a total of 13 hours, 24 minutes of daylight today (two minutes less than yesterday) and 14 hours, 23 minutes between twilights. The moon is waxing crescent. Illumination was 38% at midnight, will be 43% at noon and 48% at midnight tonight. Moonrise is at 13:35 this afternoon. Moonset is at 22:40 this evening. Moonlight time is 9 hours, 5 minutes which is 30 minutes shorter than yesterday.

Labor Day is in 12 days. Patriot Day is in 16 days. -Bernie-

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