Chicago weather historian Frank Wachowski provides these preliminary weather statistics for September 2007: With 76 percent of possible sunshine (versus a normal of 62 percent), it will enter the record books as Chicago's sunniest month in three years (sunniest since, coincidentally, September of 2004, which registered 90 percent of possible sun).
With an average temperature of 68.2 degrees (4.4 degrees above normal), this becomes the fifth warmest September since temperature observations began at O'Hare Airport in 1959.
Finally, September delivered 1.09 inches of rain -- only one-third of the normal monthly total of 3.27 inches.
And the warm temperature regime continues. Chicago's afternoon readings are forecast to reach or exceed 80 degrees on four of the next six days, but the climatological expectation in early October is only one day out of six.
A few thunderstorms are possible late Sunday and again late Tuesday.
--By Richard Koeneman, WGN Weather Center Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
