July 25: ORD

Today is July 25th. It's the 206th day of the year. 159 days remain. It's week 30 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 64. I've calculated the 31-year averages at 84 and 65.

On the hot side, there were no days of a mean of at least 11.5 degrees above normal. In 1987 the high was 95 with a low of 74. In 1999 the high was 96 with a low of 73. Another warm low was 73 in 2006. The record high of 101 was set in 1940. The record warmest low of 77 occurred back in 1892. 21 of the last 31 highs (68%) were 80s. Four highs were in the warmer 90s. Six 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 1970 today and tomorrow (25th & 26th) the temperatures were the same: a high of 89 with a low of 71. In 1965 the high was 88 with a low of 58, a 30 degree spread.

More recently, there were no large or small temperature spreads.

On the cool side, there were no days of a mean of at least 11.5 degrees below normal. In 2004 the high was just 73, the coolest high of the past 31 years. The record coolest high of 64 occurred in 1920. The cool lows were 57 in both 1998 and 2000. The record low of 53 was set in 1911. 19 of the last 31 lows (61%) were 60s. Four lows were in the cooler 50s. Eight lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:07 and sunrise was at 5:39. Sunset is at 20:20 and civil twilight ends at 20:52. Nautical twilight ends at 21:33 and astronomical twilight ends at 22:19. There's a total of 14 hours, 41 minutes of daylight today and 15 hours, 45 minutes between twilights. Tomorrow twilight begins at 5:08 and sunrise is at 5:40. The moon is waxing gibbous and will be completely full tonight at 20:27 (the full Buck or Thunder moon). Illumination was 99% at midnight, will be 100% at noon and 100% at midnight tonight. Moonset was at 5:12 this morning. Moonrise is at 20:05 tonight. Moonset is at 6:14 tomorrow morning. Moonlight time is 9 hours, 7 minutes which is 30 minutes longer than yesterday.

Parent's Day is today. - Bernie -