Here are the monthly precipitation and temperatures for 2013 in Illinois through September, expressed as departures from the 1981-2010 average. Regarding precipitation, we had a very wet start to 2013 through June, the wettest first half of a year on record, which then turned into a dry July-September. The year to date precipitation totals stands at 35.58 inches, which is 4.85 inches above average.
Regarding temperatures, January was very mild while March was much colder than average. We had slightly cooler than average temperatures in the summer months of June, July, and August, followed by a September that was on the warm side. The year to date temperature stands at 54.6 degrees, which is 0.9 degrees below average.