June 9: ORD

Today is June 9th. It's the 160th day of the year. 205 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.

According to the National Climatic Data Center (NCDC), the normal high is 78 and the normal low is 55. I've calculated the 32-year averages at 76 and 56.

On the hot side, in 1999 the high was 90 with a low of 67. In 2000 the high was 87 with a low of 67. Another warm low was 70 in 1984, our only 70s low. The record high of 98 was set back in 1911. The record warmest low of 77 occurred back in 1914. 31 of the past 32 highs (97%) were in the: 60s (9), 70s (10) and 80s (12). One high was in the hot 90s.

Yesterday, June 8, 2011, was the second warmest June 8th in the history of O'Hare International Airport. Yesterday bested 1999 (high of 92, low of 68) by just half a degree. 2004 remains the warmest, having a high of 91 and low of 74. Yesterday was also the 9th high to reach 90 degrees, the 6th in the past 33 years. If it hadn't been for a cold front late in the day, yesterday probably would've been the warmest. The high was 95 with a low of 66. As you can see, the warmth of the low temperature has just as much to do with the rankings as a day's high temperature.

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 76 with a low of 44, a 32 degree spread. In 1976 the high was hot 90 degrees. In 1969 the low was a cold 43 degrees. In 1968 the high was a hot 93 with a low of 65, a hot day. In 1967 the low was a warm 70 degrees. In 1966 the high was a cool 61 with a low of 48, a cool day. In 1964 the high was 91 with a low of 69, a hot day. In 1963 the high was a hot 90 degrees. In 1962 the low was a warm 67 degrees. In 1959 the high was 90 with a low of 71, a hot day.

More recently, there were small spreads of six degrees in 1996 (60/54) and six degrees in 1998 (64/58). The large spreads were: 33 degrees in 1994 (73/40), 31 degrees in 2001 (81/50), 31 degrees in 2002 (87/56) and 30 degrees in 1991 (86/56).

On the cool side, in 1988 the high was 63 with a low of 49. In 1980 the high was 69 with a low of 43. Other cool highs were 60 in 1996, 64 in 1998, 66 in 1987 and 66 in 1989. Another cold low was the record low of 40 in 1994 (the former record low was 42 in 1977). The record coolest high of 54 occurred back in 1915. 25 of the last 32 lows (78%) were in the: 50s (15) and 60s (10). Six lows were in the cooler 40s. Our most recent 40s low was 48 in 1997. One low was in the warmer 70s.

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 gained no minutes of daylight from yesterday. Tomorrow twilight begins at 4:42 and sunrise is at 5:17. The moon reached first quarter last night at 21:11 and is waxing gibbous. Illumination was 52% at midnight, will be 58% at noon and 63% at midnight tonight. Moonset is at 0:56 this morning. Moonrise is at 13:41 this afternoon. Moonset is at 1:24 tomorrow morning. Moonlight time is 11 hours, 15 minutes which is 43 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. Flag Day is in five days. Father's Day is in ten days.