National Weather Service Weather Forecast Office

August featured a return to near normal rainfall for much of central and eastern Illinois, while conditions across the west remained dry.  Temperatures were typcial compared to climatological averages.  Several weather systems affected the area during the month which produced scattered reports of severe weather.  Two of the more significant events were:

• August 9th - Mid-afternoon thunderstorms produced estimated 80-90 mph downburst winds along with quarter sized hail produced significant damage on the west side of Bloomington.  Sporadic wind damage continued as the storms shifted southeast near Champaign and Paris, in addition to small hail.
• August 16th - The hardest hit areas were from storms that tracked from northern Montgomery County eastward to around Charleston/Mattoon during the early afternoon.  Extensive damage occurred to trees and power lines, especially around Pana and Windsor.  A storm chaser measured a 78 mph wind gust near the Moultrie/Coles county line.  As the storms pushed to the I-70 corridor, they produced a 74 mph wind gust at the Effingham airport.  The storms were largely out of southeast Illinois by around 6 pm.

Maps below from the Midwestern Regional Climate Center highlight rainfall and temperature comparisons to normal across the Midwest for the month.

Summer 2012 will go down in the record books as one of the driest on record for several locations in central and southeast Illinois.  This dryness produced one of the most significant droughts across the area since the mid 1950s.  By late summer, extreme drought covered much of the area, while exceptional drought affected far southeast Illinois.  The drought led to significant crop losses, water restrictions, and enhanced fire danger. 

For the summer period (June through August) rainfall totals were less than 50% of normal for large parts of central and southeast Illinois.  For the official climate sites, Lincoln set their 2nd driest summer on record (3.41" vs 13.30" normal), and Springfield set their 4th driest summer on record (4.22" vs 11.64" normal).   Summer temperatures averaged only slightly above normal, thanks in large part to the very dry air which produced cooler overnight low temperatures than normal.  June and August temperatures were near normal while July was exceptionally hot.  July saw a record number of 90+ degree high temperatures for several cities along with many days which had highs above 100 degrees.