A Wet August Wraps Up a Cool, Wet Summer in Illinois

[September 05, 2014]  CHAMPAIGN - The 12th wettest August in Illinois finishes out the 10th wettest summer on record. While August was slightly warmer than average, the summer was cooler than average, according to Illinois State Climatologist Jim Angel, Illinois State Water Survey, University of Illinois.

The statewide average precipitation for August was 5.18 inches, 1.59 inches above average. The wettest area of the state was Cook County. The largest monthly total was from a site in Cicero with 10.20 inches of precipitation. There were a few areas in the northwest and east-central Illinois with only 2 to 3 inches of rainfall.

The statewide temperature for August was 73.9 degrees F, 0.3 degrees above the 1981-2010 average. The first half of August was exceptionally cool, like July, with temperatures about 3 degrees below average. The second half of August was much warmer, with temperatures about 3 degrees above average. The result was a near-average August.

The statewide average precipitation for summer was 14.96 inches, 3.09 inches above average and the 10th wettest summer on record. The wettest summer was 1993 with 18.51 inches.

For the three summer months of June, July, and August, the statewide average temperature was 72.4 degrees, 1.2 degrees below average and the 30th coolest summer season on record. The milder August knocked this summer out of the running for one of the coolest on record.

“That is not necessarily bad from an agricultural point of view,” Angel said. “The warmer August helped to keep crops on track to mature this fall.”

The outstanding colder-than-average months for 2014 were January, February, March, and July. The rest of the months have been near average.

[Text received; LISA SHEPPARD, ILLINOIS STATE WATER SURVEY]