June 23: ORD

Today is June 23rd. It's the 174th day of the year. 191 days remain. It's week 25 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 59. I've calculated the 31-year averages at 81 and 60.

On the hot side, last year the high was 94 with a low of 71. In 1997 the high was 92 with a low of 72. Five years later, in 2002, the high was 92 with a low of 72 as well. The other hot highs were 93 in both 1983 and 2005. The record high of 97 was set back in 1930. The record warmest low of 79 occurred back in 1923. 23 of the last 31 highs were: 70s (10) and 80s (13). Six highs were in the hot 90s. Two highs were in the cooler: 50s (1) and 60s (1).

In looking back through the years to the first June at O'Hare in 1959, the following instances were notable: In 1974 the high was a cool 63 with a low of 51, a cool day. In 1972 the high was 70 with a cool low of 44, a cool day. In 1969 the high was a cool 67. In 1968 the high was a hot 94 with a low of 58, a 36 degree spread. In 1963 the high was 84 with a low of 44, a 40 degree spread. The lows of 44 in 1963 and 1972 unofficially tied the record low.

More recently, there was one small spread of five degrees two years ago in 2007 (67/62). The other spreads were large: 33 degrees in 2005 (93/60), 31 degrees in 1982 (75/44), 31 degrees in 1983 (93/62) and 31 degrees in 1993 (87/56).

On the cool side, in 1979 the high was 59 with a low of 50. The record coolest high of 58 occurred at Midway in 1979. Another cool low was the record low of 44, set in 1982. Another cool high was 67 in 2007. 27 of the last 31 lows were: 50s (14) and 60s (13). One low was in the cooler 40s and three lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:43 and sunrise was at 5:18. Sunset is at 20:34 and twilight ends at 21:08. There's a total of 15 hours, 16 minutes of daylight today and 16 hours, 25 minutes between twilights. Tomorrow twilight begins at 4:43 and sunrise is at 5:18. The moon is waxing gibbous. Illumination was 89% at midnight, will be 92% at noon and 95% at midnight tonight. Moonset was at 2:42 this morning. Moonrise is at 18:22 and moonset is at 3:27 tomorrow morning. Moonlight time is 8 hours, 20 minutes which is 17 minutes shorter than yesterday.

Independence Day is in 11 days. - Bernie -