July 14: ORD

Today is July 14th. It's the 196th day of the year. 170 days remain. It's week 28 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. Before this, the official site of record was on the south side of Chicago at Midway International Airport (MDW), beginning on Wednesday, July 1, 1942. From Friday, January 1, 1926 through Tuesday, June 30, 1942, the official site was at the University of Chicago. Before that, the official site was at various locations in Chicago going back to Monday, October 16, 1871. Observations taken from October 15, 1870 to October 8, 1871 were lost in the Great Chicago Fire.

According to the National Climatic Data Center (NCDC), the normal high is 85 and the normal low is 64. I've calculated the 33-year averages at 85 and 64.

On the hot side, in 1995 (O'Hare's warmest July 14th) the high was the co-record high of 100 with the record warmest low of 83. In 1988 the high was the co-record high of 100 with a low of 69, a 31 degree spread. In 1980 the high was 97 with a low of 71. 17 of the past 33 highs (52%) were in the 80s. 11 consecutive 80s highs (65% of them) occurred from 1999 through 2009. O'Hare also recorded another six 80s highs over the past 33 years. Eight highs (24%) were in the hot: 90s (6) and 100s (2). Eight highs (24%) were in the cool: 60s (1) and 70s (7). From 1979 onward, all of the 70s highs occurred from 1987 through 1996, most recently 77 in 1996. O'Hare's second warmest July 14th was in 1977 as the high was 98 with a low of 77. The third warmest was the prior year of 1976 as the high was 98 with a low of 72. 1974 was also a warm day as the high was 95 with a low of 74.

In looking back through the years to the first July at O'Hare in 1959, the following instances were notable: In 1977 the high was 98 with a low of 77, a hot day. In 1976 the high was a hot 98 with a low of 72, a hot day. In 1967 the high was 70 with a low of 51, a cool day. That low of 51 was colder than the record low. In 1962 the high was a cool 69 with a low of 62, a seven degree spread. In 1960 the high was a cool 71 degrees.

More recently, there was an additional large spread of 32 degrees in 2002 (88/56).

On the cool side, in 1990 the high was 65 (O'Hare's coolest high of the date) with a low of 60, a spread of five degrees. A couple of years later, in 1992, the high was 70 with a low of 60. The record low of 52 was set back in 1926. The record coolest high of 64 occurred back in 1930. Both records were set at the University of Chicago. 20 of the last 33 lows (61%) were in the 60s. Six lows (18%) were in the cold 50s. Seven lows (21%) were in the warm: 70s (6) and 80s (1). O'Hare's coolest July 14th was in 1967 as the high was 70 with a low of 51, a low colder than the record low and O'Hare's coldest low of the date.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:56 and sunrise is at 5:30. Sunset is at 20:28 and twilight ends at 21:02. There's a total of 14 hours, 58 minutes of daylight today and 16 hours, 6 minutes between twilights. We lost two minutes of daylight from yesterday. Tomorrow twilight begins at 4:57 and sunrise is at 5:31. The moon is waning crescent. Illumination was 22% at midnight, will be 18% at noon and 14% at midnight tonight. Moonrise was at 1:45 this morning. Moonset is at 16:53 this afternoon. Moonrise is at 2:28 tomorrow morning. Moonlight time is 15 hours, 8 minutes which is 19 minutes longer than yesterday.

Summer began on June 4th and runs for 110 days through September 21st. High temperatures in this period are usually in the 70s and 80s. Highs in the 90s and 100s occur infrequently. Parent's Day is in eight days.