Monday, July 6, 2009

July 6: ORD

Today is July 6th. It's the 187th day of the year. 178 days remain. It's week 27 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 83 and the normal low is 62. I've calculated the 30-year averages at 84 and 61.


On the hot side, there were no days of a mean of 11.5 degrees or more above normal. In 1988 the high was the record high of 99.
The other 90s highs were 96 in 1991, 95 in 1989, 94 in 1994, 94 in 1982, 92 in 1987 and 92 in 1986. The record warmest low of 80 was set in 1977. 15 of the last 30 highs were 80s. Seven highs were in the warmer 90s. Eight highs were in the cooler: 60s (1) and 70s (7).

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1977 the high was 96 with a low of 78, a hot day. In 1969 the high was 65 with a low of 61, a four degree spread. In 1968 the high was 81 with a low of 49, a 32 degree spread. In 1967 the high was 76 with a low of 46 (tied with the record), a 30 degree spread. In 1965 the high was 80 with a low of 42 (colder than the record), a 38 degree spread. In 196
1 the high was 78 with a low of 48, a 30 degree spread.

More recently, there were large spreads of:
33 degrees in 1988 (99/66), 33 degrees in 1989 (95/62), 31 degrees in 2001 (81/50), 30 degrees in 1981 (88/58) and 30 degrees in 1996 (88/58).

On the cool side, in 1983 the high was 71 with the co-record low of 46. Four years earlier, in 1979, the high was 78 with a low of 43. That low of 43 was colder than the record low! The other co-record low is 46, set at Midway in 1979. Other cool lows were 50 in 1984, 50 in 2001, 51 in 1992 and 52 in 1980. Another cool high was 69 in 1990. The record coolest high of 63 occurred way back in 1873. 25 of the last 30 lows were: 50s (11) and 60s (14). Two lows were in the cooler 40s and three lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:50 and sunrise was at 5:24. Sunset is at 20:32 and twilight ends at 21:06. Tomorrow twilight begins at 4:50 and sunrise is at 5:24. There's a total of 15 hours, 8 minutes of daylight today and 16 hours, 16 minutes between twilights. The moon is waxing gibbous, heading towards the full Buck moon tomorrow at 4:21. Illumination was 99% at midnight, will be 100% at noon and 100% at midnight tonight. Moonset was at 4:27. Moonrise is at 20:22 tonight. Moonset is at 5:26 tomorrow. Moonlight time is 8 hours, 5 minutes which is 13 minutes longer than yesterday.

My mom celebrates a birthday in four days. A niece of mine, Katy, celebrates a birthday in 12 days. -Bernie-

No comments: