June 18: ORD

Today is June 18th. It's the 169th day of the year. 196 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 80 and the normal low is 59. I've calculated the 31-year averages at 82 and 59.

On the hot side, in 1995 the high was 93 with the only 70s low of 71. A year earlier (1994) the high was 94 with a low of 68. The other 90s highs were 95 in 1987, 92 in 1988, 91 in 2001 and 90 in 2003. The record high of 98 was set in 1954. The record warmest low of 77 occurred in 1921. 23 of the last 31 highs were: 70s (9) and 80s (14). Six highs were in the 90s. 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 1974 the high was 81 with a low of 51, a 30 degree spread. In 1965 the high was 75 with a low of 44, a 31 degree spread. In 1963 the high was 85 with a low of 53, a 32 degree spread. In 1961 the high was 81 with a low of 51, a 30 degree spread.

More recently, five spreads were large: 36 degrees in 1988 (92/56), 33 degrees in 2003 (90/57), 32 degrees in 1993 (85/53), 30 degrees in 1986 (81/51) and 30 degrees in 1987 (95/65).

On the cool side, there were no days of means of at least 11.5 degrees lower than normal. In 1999, the record low of 45 was established. The cool highs were 64 in 1982 and 66 in 1979. The record coolest high of 55 occurred in 1950. 29 of the last 31 lows have been: 50s (16) and 60s (13). One low was in the cooler 40s and one low was in the warmer 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight began at 4:42 and sunrise was at 5:17. Sunset is at 20:33 and twilight ends at 21:07. There's a total of 15 hours, 16 minutes of daylight today and 16 hours, 25 minutes between twilights. Tomorrow twilight begins at 4:42 and sunrise is at 5:17. The moon is waxing crescent and reaches first quarter tonight at 23:29. Illumination was 39% at midnight, will be 45% at noon and 51% at midnight tonight. Moonset was 8 minutes past midnight this morning. Moonrise is at 12:31. Moonset is at 34 minutes past midnight tomorrow morning. Moonlight time is 11 hours, 37 minutes which is an hour and 5 minutes shorter than yesterday.

Father's Day is in two days and Independence Day is in 16 days. - Bernie -