The remains of Hurricanes Gustav and Ike boosted rainfall totals in Illinois for September. September statewide precipitation was 8.0 inches, 4.8 inches above normal and the third wettest September on record, according to State Climatologist Jim Angel of the Illinois State Water Survey (http://www.sws.uiuc.edu).
Combined with above-normal precipitation since the start of 2008, the January-September total was 42.8 inches, 12.4 inches above normal and the second wettest January-September on record. Only 1993 was wetter with 42.9 inches.
The remains of Hurricanes Gustav and Ike traveled a similar path, resulting in the heaviest rains falling in a wide band that ranged from Quincy in western Illinois to Chicago. Amounts within this band were in excess of 10 inches. Three sites reported amounts in excess of 14 inches.
September statewide temperatures averaged 67 degrees, only one-half a degree above normal.
"Average dates for the first time we hit 32 degrees in the fall range from October 7 in northern Illinois and October 14 in central Illinois, to October 21 in southern Illinois. The actual dates vary quite a bit from year to year, but usually occur within two weeks of the average. This year, a few sites in far northern Illinois have reached that point already by the morning of October 4," concludes Angel.
The National Weather Service (NWS) forecasts for both the month of October and the three-month October-December period call for equal chances of above, below, or near-normal temperatures and precipitation.
The Illinois State Water Survey, at the University of Illinois at Urbana-Champaign under the Institute of Natural Resource Sustainability, is the primary agency in Illinois concerned with water and atmospheric resources.