June 11: ORD

Today is June 11th. It's the 162nd day of the year. 203 days remain. It's week 24 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 78 and the normal low is 57. I've calculated the 32-year averages at 79 and 56.

On the hot side, in 2005 the high was 88 with the only 70s low of 72. In 1999 the high was 90 with a low of 66. The only other 90s high was 90 in 1983. Another warm low was 69 in 2002. The record high of 97 was last tied in 1954 after originally being set back in 1933. The record warmest low of 77 occurred in 1973. 24 of the past 32 highs (75%) were in the: 70s (9) and 80s (15). Our most recent 70s high was 76 in 1998. Two highs (6%) were in the hot 90s. Six highs (19%) were in the cool: 50s (1) and 60s (5).

In looking back through the years to the first June at O'Hare in 1959, the following instances were notable: In 1976 the high was a hot 93 with a low of 65, a hot day. In 1973 the high was 91 with a low of 71, a hot day and year of the record warmest low. In 1972 the high was 74 with a cold low of 36, a 38 degree spread and overall cool day. That low of 36 was cooler than the record low. In 1970 the high was 87 with a warm low of 70, a warm day. In 1966 the high was 78 with a cold low of 41, a 37 degree spread. In 1963 the high was a cool 65 degrees. In 1961 the high was a hot 90 with a low of 56, a 34 degree spread. In 1959 the low was a warm 69 degrees.

More recently, the spreads were all large: 40 degrees in 1988 (87/47), 34 degrees in 1982 (77/43), 34 degrees in 1994 (85/51), 32 degrees in 1983 (90/58), 32 degrees in 1989 (76/44), 32 degrees in 1992 (83/51) and 30 degrees in 1990 (80/50).

On the cool side, in 1985 the only 50s high of 56 occurred with a low of 48. In 1980 the high was 74 with the record-tying low of 41, a 33 degree spread. The record low of 41 was originally set at Midway International Airport in 1972. The other cool lows were 43 in 1982 and 44 in 1989. Two years ago, in 2009 and in 2006 the highs were a cool 64 degrees. The record coolest high of 48 was set way back in 1903. 26 of the last 32 lows (81%) were in the: 50s (16) and 60s (10). Five lows were in the cold 40s. All of the 40s lows over the last 32 years occurred from 1980 to 1989. One low (72 in 2005) was in the warm 70s. There have been only three 70s lows on this date in the history of O'Hare International Airport.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:42 and sunrise is at 5:17. Sunset is at 20:30 and twilight ends at 21:04. There's a total of 15 hours, 13 minutes of daylight today and 16 hours, 22 minutes between twilights. We gained one minute of daylight from yesterday. Tomorrow twilight begins at 4:42 and sunrise is at 5:16. The moon is waxing gibbous. Illumination was 74% at midnight, will be 79% at noon and 84% at midnight tonight. Moonset is at 1:55 this morning. Moonrise is at 16:08 this afternoon. Moonset is at 2:30 tomorrow morning. Moonlight time is 9 hours, 47 minutes which is 43 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. Flag Day is in three days. Father's Day is in eight days.