August 9: ORD

Today is August 9th. It's the 221st day of the year. 144 days remain. It's week 32 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 82 and the normal low is 63. I've calculated the 31-year averages at 84 and 64.

On the hot side, there were no days of a mean of at least 11.5 degrees above normal. The hottest days were: last year with a high of 91 and record tying warmest low of 77 (the record was 77 which occurred back in 1934) and 2001 with a high of 95 and low of 72. Another high of 95 occurred in 2005. There were two highs of 93 (1984 and 1992). The record high of 97 was set back in 1913. Over the last 31 years, 15 highs were 80s. Eight 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 August at O'Hare in 1959, the following instances were notable: In 1976 the high was 83 with a cool low of 51, a 32 degree spread. That low of 51 equals the record low. In 1972 the low was a cool 51, equal to the record low. In 1964 the high was 70 with a low of 45, a cool day. The high on the 7th in 1964 was 92. That's quite a fall to today's 45.

More recently, there were large spreads of 34 degrees in 1985 (90/56) and 30 degrees in 2005 (95/65). The small spread was seven degrees in 1983 (79/72).

On the cool side, in 1994 the high was a cool 66 with a low of 53. That high was the only 60s high. The other mid 50s lows were 54 in 1999, 55 in 1990, 56 in 1982 and 56 in 1985. The record low of 51 was set in 1972. The record coolest high of 64 was set way back in 1884. The official thermometer was located near Lake Michigan at the time. Over the last 31 years, 16 lows were in the 60s. Nine lows were in the cooler 50s and six lows were in the warmer 70s, including last year's record warmest low of 77.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:24 and sunrise was at 5:54. Sunset is at 20:03 and civil twilight ends at 20:33. Nautical twilight ends at 21:11 and astronomical twilight ends at 21:52. There's a total of 14 hours, 9 minutes of daylight today and 15 hours, 9 minutes between twilights. We are losing about two minutes of daylight a day. Tomorrow twilight begins at 5:25 and sunrise is at 5:55. The moon is reaches new tonight at 22:08. Illumination was 1% at midnight, will be 0% at noon and 0% at midnight tonight. Moonrise was at 5:15 this morning. Moonset is at 19:38 tonight. Moonrise is at 6:35 tomorrow morning. Moonlight time is 14 hours, 23 minutes which is 42 minutes shorter than yesterday. -Bernie-