July 2: ORD

Today is July 2nd. It's the 183nd day of the year. 182 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 82 and the normal low is 61. I've calculated the 32-year averages at 82 and 60.

On the hot side, in 2002 the high was 93 with a low of 75. In 1991 the high was 96 with a low of 68. The record high of 99 was set in 1970. The record warmest low of 79 occurred back in 1911. 20 of the last 32 highs (63%) were in the 80s. Two highs (6%) were in the hot 90s. Ten highs (31%) were in the cool 70s.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1978 the high was 73 with a low of 66, a seven degree spread. In 1973 the low was a warm 74 degrees. In 1970 the high was 95 with a low of 78, a hot day and year of the record high of 99 at Midway. In 1968 the high was a cool 67 with a low of 51, a cool day. In 1966 the high was 93 with a low of 59, a 34 degree spread.

More recently, there were large spreads of: 34 degrees in 1984 (83/49) and 32 degrees in 1979 (82/50).

On the cool side, in 2001 the high was 75 with the record low of 49. The record low of 49 was originally set in 1984. In 1982 the high was 73 with a low of 51. The coolest high was 70 in 1994. The record coolest high of 62 occurred in 1940. 29 of the last 32 lows (91%) were in the: 50s (14) and 60s (15). Two lows were in the cold 40s and one was in the warm 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:47 and sunrise is at 5:21. Sunset is at 20:33 and twilight ends at 21:08. There's a total of 15 hours, 12 minutes of daylight today and 16 hours, 21 minutes between twilights. We lost a minute of daylight from yesterday. Tomorrow twilight begins at 4:47 and sunrise is at 5:22. The moon reached new yesterday morning at 3:54 and is waxing crescent. Illumination was 1% at midnight, will be 2% at noon and 4% at midnight tonight. Moonrise is at 6:45 this morning. Moonset is at 21:28 tonight. Moonrise is at 7:56 tomorrow morning. Moonlight time is 14 hours, 43 minutes which is 30 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. Independence Day is in two days.