July 8: ORD

Today is July 8th. It's the 189th day of the year. 176 days remain. It's week 27 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 83 and the normal low is 63. I've calculated the 32-year averages at 85 and 64.

On the hot side, in 1981 the high was 94 with a low of 77. In 2007 the high was 94 with a low of 75. The other 90s highs of note were 97 in 1988, 95 in 1990 and 93 in 2002. The record high of 99 was set in 1955. The record warmest low of 78 occurred way back in 1881. 17 of the past 32 highs (53%) were in the 80s. Nine highs (28%) were in the hot 90s. Six highs (19%) were in the cool: 60s (1) and 70s (5). The lone 60s high occurred two years ago, in 2009, at 65 degrees.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1969 the high was a cool 71 degrees. In 1961 the high was 72 with a cool low of 51, a cool day.

More recently, there was a large spread of 32 degrees in 1983 (85/53).

On the cool side, in 1984 the high was 74 with the record low of 48. Two years ago (2009) was the second coolest July 8th (of the past 32) as the high was 65 with a low of 61, a small four degree spread. The record coolest high of 60 occurred way back in 1883. 16 of the last 32 lows (50%) were in the 60s. Nine lows (28%) were in the cool: 40s (1) and 50s (8). Seven lows (22%) were in the warm 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:51 and sunrise is at 5:25. Sunset is at 20:32 and twilight ends at 21:06. There's a total of 15 hours, 7 minutes of daylight today and 16 hours, 15 minutes between twilights. We lost a minute of daylight from yesterday. Tomorrow twilight begins at 4:52 and sunrise is at 5:26. The moon reaches first quarter this morning at 1:29. Illumination was 50% at midnight, will be 56% at noon and 61% at midnight tonight. Moonset was at 23:58. Moonrise is at 13:57 this afternoon. Moonset is at 0:31 tomorrow morning. Moonlight time is 10 hours, 3 minutes which is 71 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. Parent's Day is in 16 days.