Illinois Weather Normal during Summer 2001, Illinois State Water Survey

Press Release

For Immediate Release August 31, 2001
Illinois Weather Normal during Summer 2001

Jim Angel - (217) 333-0729, Fax: (217) 244-0220,
Eva Kingston - (217) 244-7270, Fax: (217) 333-6540,

"Even with the 25th coolest June, the 22nd wettest August, and Chicago reporting the second wettest August on record since 1895, Illinois temperatures and precipitation in summer 2001 were near normal," says State Climatologist Jim Angel of the Illinois State Water Survey (, a division of the Illinois Department of Natural Resources.

Illinois ended up with 110 percent of normal precipitation (12.49 inches) and temperatures slightly cooler than normal (-0.2 degrees).

"But the real weather story was how conditions changed across the state from June through August and in different portions of the state," continues Angel.

Hot, dry conditions prevailed across all but extreme northern and southern Illinois from mid-July to mid-August with rainfall only 50 to 75 percent of normal. Temperatures were two degrees above normal in most of the state. "Unfortunately, these conditions occurred at a critical time in the development of corn and soybeans, leading to potentially reduced yields in some areas," says Angel.

Looking back on the summer, temperatures statewide were cooler than normal in June, the 25th coolest June since 1895. "Above normal precipitation provided some relief from dry springtime conditions in southern Illinois. However, along with the precipitation came thunderstorms that resulted in one tornado and numerous reports of hail and high winds," says Angel.

Illinois temperatures and precipitation were normal in July. After a cool beginning, high humidity and high temperatures in the second half of July stressed plants, animals, and people. Chicago reported at least 9 heat-related deaths July 20-24, and the heat index reached 110oF at O'Hare Airport on July 23. The southern third of the state enjoyed above normal rainfall (172 percent of normal in the southwest) while central and northern Illinois were dry with monthly rainfall only 63 percent of normal in east-central Illinois. July also had lots of severe weather that included hail and wind damage statewide.

With 4.59 inches of rainfall statewide, August ended up as the 22nd wettest August since 1895. Temperatures were 1.2 degrees above normal. "Unfortunately, the first two weeks were hot and dry with most of the rainfall in the third week, too late to benefit most crops," says Angel. Despite plentiful rainfall, precipitation was below average in a band between Carthage and DeKalb, an area around Lawrenceville to the southeast, and an area around Carbondale to the southwest.

"Highly variable summer rainfall is pretty typical of summertime storm-produced rainfall. While 12.25 inches fell at O'Hare Airport in August--making this the second wettest August on record in Chicago--DeKalb, only 50 miles west, had 2.79 inches," continues Angel.

Severe weather in August, and there was a lot of it, ranged from a storm that dumped nearly 5 inches of rainfall on the Chicago Loop within a 3-hour period to thunderstorms on August 18 that produced four tornadoes and reports of 3 -inch hail in central Illinois.

"Despite all this severe weather, preliminary reports indicate that there were no fatalities and no widespread damages from the five tornadoes that struck Illinois this summer. The unofficial year-to-date count is 10 tornadoes compared to an annual average of 28 tornadoes for the state," concludes Angel.

| News |

Illinois State Water Survey

2204 Griffith Dr
Champaign, IL 61820-7463

Terms of use. Email the Web Administrator with questions or comments.

© 2018 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois State Water Survey.
Site Map