June 28: ORD

Today is June 28th. It's the 179th day of the year. 186 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 60. I've calculated the 32-year averages at 83 and 61.

On the hot side, in 2005 the high was 94 with a low of 76. In 1991 the high was 89 with a low of 70. The only other 90s high of the past 32 years was 92 in 1996. The record high of 101 was originally set in 1952 and tied in 1971. The record warmest low of 81 occurred back in 1913. 21 of the past 32 highs (66%) were in the 80s. Two highs (6%) were in the hot 90s. Nine highs (28%) were in the cool: 60s (1) and 70s (8). The lone 60s high was 69. It occurred on the coolest day of the past 32 years in 2000.

In looking back through the years to the first June at O'Hare in 1959, the following instances were notable: In 1973 the high was a cool 70 degrees. In 1971 the high was 97 with a low of 75, a hot day and year of the record high (101 at Midway). In 1964 the high was 91 with a low of 61, a 30 degree spread. In 1962 the high was 90 with a low of 57, a 33 degree spread. In 1959 the high was 88 with a warm low of 78, a hot day.

More recently, there was a small spread of seven degrees in 1983 (70/63). The other spreads were large: 30 degrees in 1996 (92/62) and 30 degrees in 1988 (88/58).

On the cool side, in 2000 the high was 69 (our only 60s high) with a low of 55. In 1992 the high was 82 with the record low of 44 (our only 40s low), a spread of 38 degrees. The other cool high was 70 in 1983. The record coolest high of 58 occurred way back in 1902. 20 of the last 32 lows (63%) were in the 60s. Ten lows (31%) were in the cool: 40s (1) and 50s (9). Two lows (6%) were in the warm 70s.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:45 and sunrise is at 5:19. Sunset is at 20:34 and twilight ends at 21:08. There's a total of 15 hours, 15 minutes of daylight today and 16 hours, 23 minutes between twilights. We lost no minutes of daylight from yesterday. Tomorrow twilight begins at 4:45 and sunrise is at 5:20. The moon is waning crescent. Illumination was 10% at midnight, will be 7% at noon and 5% at midnight tonight. Moonrise is at 2:52 this morning. Moonset is at 18:21 this afternoon. Moonrise is at 3:39 tomorrow morning. Moonlight time is 15 hours, 29 minutes which is 19 minutes longer 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 six days.