July 10: ORD

Today is July 10th. It's the 191st day of the year. 174 days remain. It's week 28 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 63. I've calculated the 31-year averages at 84 and 63.

On the hot side, in 1989 the high was 101 (a degree off the record) with a low of 73. Five years earlier, in 1984, the high was 99. The record high of 102 and record warmest low of 80 were set on the same day back in 1936. 14 of the last 31 highs were 80s. Nine highs were in the warmer: 90s (8) and 100s (1). Eight highs were in the cooler 70s.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1976 the high was 97 with a low of 76, a hot day. In 1968 the high was 67 with a low of 53, a cool day. In 1966 the high was a hot 97. In 1965 the high was 80 with a cool low of 50 (equal to the record), a 30 degree spread. In 1963 the high was 83 with a cool low of 45 (lower than the record), a 38 degree spread. In 1962 the high was 84 with a cool low of 51 (just above the record), a 33 degree spread.

More recently, there were large spreads of: 35 degrees in 1981 (91/56), 33 degrees in 1984 (99/66) and 31 degrees in 2005 (91/60).

On the cool side, there were no days of a mean of 11.5 degrees or more below normal. The coolest lows were the co-record lows of 50 in both 1996 and 1997. The coolest high was 73 in 2006. The record coolest high of 62 occurred back in 1917. 23 of the last 31 lows (74%) were 60s. Seven lows were in the cooler 50s and one was in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:52 and sunrise was at 5:26. Sunset is at 20:31 and twilight ends at 21:05. There's a total of 15 hours, 5 minutes of daylight today and 16 hours, 13 minutes between twilights. Tomorrow twilight begins at 4:53 and sunrise is at 5:27. The moon is waning crescent and will be new tomorrow at 14:40. Illumination was 3% at midnight, will be 2% at noon and 0% at midnight tonight. Moonrise was at 3:56 this morning. Moonset is at 19:45 and moonrise is at 5:08 tomorrow morning. Moonlight time is 15 hours, 49 minutes which is 7 minutes shorter than yesterday (it peaked at 15:56).

NASCAR is at my home track, the Chicagoland Speedway (Joliet, IL) tonight. It's the Sprint Cup/LifeLock 400. Last night in the Nationwide Series (The Dollar General 300), Kyle Bush won. Parent's Day is in 15 days. - Bernie -