June 30: ORD

Today is June 30th. It's the 181st day of the year. 184 days remain. It's week 26 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 82 and the normal low is 61. I've calculated the 31-year averages at 80 and 60.

On the hot side, in 1996 the high was 94 with a low of 73. The other 90s highs were 93 in 2002, 91 in 1990 and 91 in 2005. The only other 70s low was 72 in 2005. The record high of 99 was set in 1953. The record warmest low of 80 occurred back in 1931. 24 of the last 31 highs were: 70s (9) and 80s (15). Four highs were in the warmer 90s and two highs were in the cooler 60s.

In looking back through the years to the first June at O'Hare in 1959, the following instances were notable: In 1970 the high was 93 with a low of 78, a hot day. In 1968 the high was a warm 73. In 1966 the high was 90 with a low of 60, a 30 degree spread. In 1965 the high was 68 with a low of 44, a cool day. In 1963 the high was 92 with a low of 62, a 30 degree spread.

More recently, there was a small spread of five degrees in 1986 (64/59) and seven degrees last year (66/59). Last year was the 5th coolest of the past 31 years. The large spreads were: 34 degrees in 1989 (83/49), 32 degrees in 2006 (85/53) and 30 degrees in 1979 (81/51).

On the cool side, in 1982 the high was 70 with a low of 47. The other 40s low was 49 in 1989. The coolest highs were 64 in 1986 and 69 in 1993. The record low of 45 was set in 1943. The record coolest high of 59 occurred back in 1902. 27 of the last 31 lows (87%) were: 50s (17) and 60s (10). Two lows were in the cooler 40s and two lows were in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:46 and sunrise was at 5:20. Sunset is at 20:34 and twilight ends at 21:08. There's a total of 15 hours, 14 minutes of daylight today and 16 hours, 22 minutes between twilights. Tomorrow twilight begins at 4:46 and sunrise is at 5:21. The moon is waning gibbous. Illumination was 87% at midnight, will be 84% at noon and 80% at midnight tonight. Moonset was at 9:25 this morning. Moonrise is at 22:52 and moonset is at 10:25 tomorrow morning. Moonlight time is 10 hours, 33 minutes which is 38 minutes longer than yesterday.

Independence Day is in four days. - Bernie -