June 8: ORD

Today is June 8th. It's the 160th day of the year. 206 days remain. It's week 23 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 77 and the normal low is 56. I've calculated the 33-year averages at 79 and 57.

On the hot side, in 2004 (O'Hare's hottest June 8th) the high was 91 with a low of 74 (O'Hare's warmest low of the date). Last year, in 2011, the high was 95 with a low of 66. In 1999 the high was 92 with a low of 68. In 1984 the high was 86 with a low of 71. A year later, in 1985, the high was 95 with a low of 62, a 33 degree spread. In 2000 the high was 89 with a low of 66. Five years later, in 2005, the temps were the same: high of 89 with a low of 66. The other hot highs were 93 in 1979 and 91 in 1987. The record high of 97 and record warmest low of 77 were set on the same hot day back in 1933 at the University of Chicago. 14 of the past 33 highs (42%) were in the 80s. Six highs (18%) were in the hot 90s. 13 highs (39%) were in the cool: 50s (1), 60s (6) and 70s (6). Our most recent 70s high was 74 in 2001.

In looking back through the years to the first June at O'Hare in 1959, the following instances were notable: In 1978 the high was a cool 64 degrees. In 1976 the high was a hot 89 degrees. In 1969 the high was a cool 59 with a low of 45, a cool day. In 1968 the high was a hot 91 with a low of 66, a hot day. In 1967 the low was a warm 70 degrees. In 1964 the high was a hot 92 with a low of 56, a 36 degree spread. In 1963 the high was a hot 89 degrees. In 1962 the high was 85 with a low of 53, a 32 degree spread. In 1959 the high was 91 with a low of 68, a hot day.

More recently, there were additional large spreads of 38 degrees in 1983 (81/43), 36 degrees in 1979 (93/57) and 35 degrees in 1987 (91/56).

On the cool side, in 1996 the high was 61 with a low of 45. The year earlier, 1995, the high was 58 (O'Hare's coolest high of the date) with a low of 49. The other cool highs were 63 in 1994 and 66 in 1980. The other cool lows were 43 in both 1983 and 1998. These lows of 43 are O'Hare's coldest lows of the date. The record low of 42 was set way back in 1885. The record coolest high of 51 occurred back in 1913. Both records were set at a time when the official readings were taken adjacent to Lake Michigan. 31 of the last 33 lows (94%) were in the: 40s (9), 50s (11) and 60s (11). Our most recent 40s low was 48 in 2001. Two lows were in the warm 70s. O'Hare's coolest June 8th was in 1969 as the high was 59 with a low of 45.

The following astronomical data is provided by the United States Naval Observatory. In Crystal Lake, twilight begins at 4:43 and sunrise is at 5:17. Sunset is at 20:28 and twilight ends at 21:03. There's a total of 15 hours, 11 minutes of daylight today and 16 hours, 20 minutes between twilights. We didn't gain any minutes of daylight from yesterday. Tomorrow twilight begins at 4:42 and sunrise is at 5:17. The moon is waning gibbous. Illumination was 81% at midnight, will be 77% at noon and 72% at midnight tonight. Moonset was at 10:00 this morning. Moonrise is at 23:47 tonight. Moonset is at 11:07 tomorrow morning. Moonlight time is 10 hours, 13 minutes which is 36 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. Flag Day is in six days.