July 26: ORD

Today is July 26th. It's the 207th day of the year. 158 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 83 and 65.

On the hot side, there were no days of a mean of at least 11.5 degrees above normal. In 1997 the high was 97 with a low of 73. Another warm low was 73 in 1982. The record high of 99 was set in 1955. The record warmest low of 80 occurred back in 1916. 21 of the last 31 highs (68%) were 80s. Three highs were in the warmer 90s. Seven highs were in the cooler: 60s (1) and 70s (6). There have been two periods of sub 90 degree weather. The first of these was nine years from 1988 to 1996 and the second is still ongoing, 12 years from 1998 through 2009.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1972 the high was a cool 70 with a low of 63, a seven degree spread. In 1962 the high was 75 with a cool low of 49.

More recently, there was a small spread of five degrees in 1981 (71/66).

On the cool side, in 1984 the high was 67 with a low of 55. Another cool high was 71 in 1981. The record low of 53 was set in 1962 and tied in 1991. The record coolest high of 66 occurred way back in 1891. 17 of the last 31 lows were 60s. Seven lows were in the cooler 50s. Seven lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 5:08 and sunrise was at 5:40. Sunset is at 20:19 and civil twilight ends at 20:51. Nautical twilight ends at 21:32 and astronomical twilight ends at 22:17. There's a total of 14 hours, 39 minutes of daylight today and 15 hours, 43 minutes between twilights. Tomorrow twilight begins at 5:09 and sunrise is at 5:41. The moon is waning gibbous and was full last night at 20:27 (the full Buck or Thunder moon). Illumination was 100% at midnight, will be 100% at noon and 99% at midnight tonight. Moonset was at 6:14 this morning. Moonrise is at 20:32 tonight. Moonset is at 7:16 tomorrow morning. Moonlight time is 9 hours, 42 minutes which is 35 minutes longer than yesterday. -Bernie-