by Trent Ford, Illinois State Climatologist
Illinois State Water Survey
Prairie Research Center
Even though climatological fall started three weeks ago, we had to wait until this week to get our first real taste of the season. Average air temperatures most of this week were 8 to 12 degrees above normal, including a few days with highs that were 15 to 20 degrees above normal. Carbondale hit 99 degrees on Wednesday, the latest that mark has been reached in Carbondale’s record. A cold front slid through the state late in the week, bringing in much cooler and less humid air. Some places saw 20-to-25-degree differences between high temperatures on Wednesday and Thursday.
Multiple rounds of storms moved through the northern half of the state this week, including severe storms in northern and central Illinois. The storms brought very heavy rain, strong winds, and hail to several parts of the state – including reported golf ball sized hail in Morgan County. 7-day rainfall totals ranged from over 5 inches in Hancock County to less than a tenth of an inch in much of southern Illinois. In fact, much of southern Illinois has been 2-3 inches drier than normal since mid-August, spurring the US Drought Monitor to expand moderate drought in Massac County and abnormally dry conditions up to the Franklin-Jefferson County line. We’re quickly approaching the time of the year when rain – especially excessive rain – will do more harm than good on the agriculture side.
Looking ahead, the 7-day forecast remains mostly dry with mild temperatures across the state. Both the week 2 outlook and the outlook for the entire month of October lean both warmer and drier than normal statewide. Hopefully, that will spell a drawn-out season with great fall color, only time will tell.