August in Illinois Proves 12th Coolest on Record

BY DAN GRANT

What looked to be a warm growing season shifted gears in August.

The statewide temperature averaged 70.6 degrees, 3 degrees below normal, which made it the 12th-coolest August on record, according to Jim Angel, state climatologist with the Illinois State Water Survey.

And the weather reversal could continue this month as a cool forecast includes chances of an early frost, based on some models.

“Back in June and July, it was very warm. But now August was much cooler and also on the dry side,” Angel said. “Cool and dry is an interesting combination for August. We usually don’t get that mix.”

Precipitation in the state last month averaged just 2.4 inches, almost an inch below average.

“Really, the only area that was wet was a stretch from Quincy to north of Champaign, that got 3 to 5 inches,” Angel said. “Most of the rest of the state got 1 to 3 inches, which is well below normal for this time of year.”

The flip in weather conditions from July to August was most pronounced in northern Illinois.

“In August, northern Illinois was probably the driest part of the state, whereas in July they couldn’t get it to stop raining up there,” Angel said. “They went from being the wettest to the driest in one month.”

And it appears the cool, dry trend could continue this month.

The National Weather Service outlook for September shows an increased chance of below-normal temperatures and below-normal precipitation in Illinois.

“If you look at the forecast for September, it’s really more of the same,” the climatologist noted. “The fact that we are running colder than normal in August and now into September means we could have a shot at an early frost (this month as opposed to October), especially in the northern part of the state.”

That would be bad news for farmers who have late-planted crops struggling to reach maturity in the mild conditions.

And it would continue a shift in this season’s pattern, as only May and August featured below-normal temperatures in Illinois so far this year.

Meanwhile, some parts of the state continue to deal with moderate drought and abnormally dry conditions.   

“At this point, the drought is not a big concern. It doesn’t have as much impact into September,” Angel added. “But, if it continues, we could see some problems getting soil moisture recharged this fall.”