CHAMPAIGN, Ill. – Based on preliminary data in Illinois, the statewide average rainfall for September was 2.4 inches, 0.8 inches below normal. This breaks the string of months with above normal precipitation that started in February 2009 and ended in August, according to State Climatologist Jim Angel of the Illinois State Water Survey (http://www.isws.illinois.edu).

While much of southern and western Illinois received above normal rainfall, northern and eastern Illinois were drier than normal. Rainfall was heaviest in southeast Illinois, with Lawrenceville reporting 10.5 inches for the month. Many sites in northern and eastern Illinois reported totals of an inch of rain or less.

Temperatures across Illinois averaged 65.8 degrees, 0.4 degrees below normal. No site reported a freezing temperature (32 degrees or less) during the month.

"Average frost dates in Illinois range from the first week of October in northern Illinois, the second week in central Illinois, to the third week in southern Illinois. So be prepared for frost within the next week or two," concludes Angel.

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.