July 1: ORD

Today is July 1st. It's the 182nd day of the year. 183 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 32-year averages at 81 and 59.

On the hot side, in 2002 the high was 93 with a low of 75. In 1991 the high was 97 with a low of 67, a 30 degree spread. The record high of 103 was set in 1956. The record warmest low of 78 occurred back in 1931. 24 of the past 32 highs (75%) were in the: 70s (12) and 80s (12). Six highs (19%) were in the hot 90s. Two highs (6%) were in the cool 60s. These were 65 degrees two years ago (in 2009) and 66 in 1986.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1974 the high was 89 with a low of 57, a 32 degree spread. In 1970 the high was 94 with a low of 76, a hot day. In 1966 the high was 92 with a low of 61, a 31 degree spread. In 1965 the high was 81 with a cold low of 40, a 41 degree spread and cool day. In 1963 the high was a hot 95 degrees.

More recently, there were large spreads of: 34 degrees in 1989 (89/55), 33 degrees in 1979 (84/51) and 33 degrees in 1992 (91/58).

On the cool side, two years ago, in 2009, the high was 65 with a low of 57. In 1982 the high was 76 with the record low of 46, a 30 degree spread. The other cool low was 49 in 1984. These were the only 40s lows, just two years apart! The other cool highs were 66 in 1986 and 70 in 1981. The record coolest high of 61 occurred back in 1924. 29 of the last 32 lows (91%) were in the: 50s (16) and 60s (13). Two lows were in the cool 40s and one was in the warm 70s (75 in 2002).

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:46 and sunrise is at 5:21. Sunset is at 20:34 and twilight ends at 21:08. There's a total of 15 hours, 13 minutes of daylight today and 16 hours, 22 minutes between twilights. We lost a minute of daylight from yesterday. Tomorrow twilight begins at 4:47 and sunrise is at 5:21. The moon reaches new this morning at 3:54. Illumination was 0% at midnight, will be 0% at noon and 1% at midnight tonight. Moonrise is at 5:37 this morning. Moonset is at 20:50 tonight. Moonrise is at 6:45 tomorrow morning. Moonlight time is 15 hours, 13 minutes which is 18 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 three days.