July 13: ORD

Today is July 13th. It's the 194th day of the year. 171 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 84 and the normal low is 63. I've calculated the 31-year averages at 84 and 63.

On the hot side, in 1995 the high was the record high of 104 with the record low of 81. 90s highs of note were 94 in both 1988 and 1997. The warmest 70s lows were 74 in 1981 and 73 in 2005. 14 of the last 31 highs were 80s. Seven highs were in the warmer: 90s (6) and 100s (1). Ten highs were in the cooler: 60s (1) and 70s (9).

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 86 with a low of 53, a 33 degree spread. In 1974 the high was a hot 95 but technically not a hot day. In 1973 the high was 95 with a low of 72, a hot day. In 1967 the high was a cool 67 with a low of 52, a cool day. That low of 52 was equal to the record low. In 1964 the high was 71 with a low of 49, a cool day. That low of 49 was cooler than the record low.

More recently, there was a small spread of seven degrees in 1990 (66/59) and a large spread of 33 degrees in 1983 (89/56).

On the cool side, there were no days of a mean of 11.5 degrees or more below normal. A cool low was 54 in 1987. The record low of 52 was set in 1975. The cool highs were 66 in 1990 and 72 in 1994. The record coolest high of 64 occurred back in 1926. 17 of the last 31 lows were 60s. Nine lows were in the cooler 50s. Five lows were in the warmer: 70s (4) and 80s (1).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:55 and sunrise was at 5:29. Sunset is at 20:29 and twilight ends at 21:03. There's a total of 15 hours of daylight today and 16 hours, 8 minutes between twilights. Tomorrow twilight begins at 4:56 and sunrise is at 5:29. The moon is waxing crescent. Illumination was 3% at midnight, will be 5% at noon and 9% at midnight tonight. Moonrise was at 7:44 this morning. Moonset is at 21:42 and moonrise is at 9:02 tomorrow morning. Moonlight time is 13 hours, 58 minutes which is 46 minutes shorter than yesterday.

Parent's Day is in 12 days. - Bernie -