August 26: ORD

Today is August 26th. It's the 238th day of the year. 127 days remain. It's week 34 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 81 and the normal low is 62. I've calculated the 32-year averages at 82 and 63.

On the hot side, in 1993 the high was 94 with a low of 74. A decade later, in 2003, the high was 92 with a low of 71. In 1980 the high was 92 with a low of 69. In 1995 the high was 91 with a low of 69. The only other 90s high was 93 in 1991. The only other 70s low was 70 in 1990. The record high of 97 and record warmest low of 77 were set on the same hot day in 1973. The record high of 97 was originally set two decades earlier in 1953. 26 of the past 32 highs (81%) were in the: 70s (10) and 80s (16). Five highs were in the hot 90s. One high was in the cool 60s (65 in 1987).

In looking back through the years to the first August at O'Hare in 1959, the following instances were notable: In 1973 the high was 93 with a low of 75, a hot day. This was the year that the records were set at Midway Airport. In 1971 the high was a cool 68 degrees. In 1968 the high was a cool 65 with a low of 54, a cool day. In 1964 the high was 74 with a cold low of 41, a 33 degree spread and cool day. That low of 41 was colder than the record low. In 1963 the low was a cool 50 degrees. In 1959 the high was 92 with a warm low of 74, a hot day.

More recently, there were no small spreads of up to seven degrees or large spreads of at least 30 degrees.

On the cool side, in 1987 the high was our coolest high of 65 with a low of 57. In the following year, 1988, the high was 77 with a low of 54. In 1992 the high was 72 with a low of 60. Our coldest low was 54 in 1988. The record low of 47 was set way back in 1887. The record coolest high of 61 occurred way back in 1885. 21 of the last 32 lows (66%) were in the 60s. Eight lows (25%) were in the cool 50s. Three lows (9%) were in the warm 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 5:43 and sunrise is at 6:12. Sunset is at 19:38 and twilight ends at 20:07. There's a total of 13 hours, 26 minutes of daylight today and 14 hours, 24 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 5:44 and sunrise is at 6:13. The moon is waning crescent and two days from new. Illumination was 11% at midnight, will be 8% at noon and 5% at midnight tonight. Moonrise is at 3:15 this morning. Moonset is at 17:55 this afternoon. Moonrise is at 4:27 tomorrow morning. Moonlight time is 14 hours, 40 minutes which is 29 minutes shorter than yesterday.

Summer began June 4 and runs for 110 days through September 21. High temperatures in this period are usually in the 70s and 80s. Highs in the 60s, 90s and 100s occur infrequently. Labor Day is in ten days. 9/11 Remembrance Day and Grandparents Day are in 15 days.