Weekly Climate Review & Weather Forecast
Thankfully, our weather calmed down this week. Temperatures this week ranged from the high 60s in northern Illinois to the mid-70s in southern Illinois, between 2 and 6 degrees below normal for mid-July. July to date has been 1 to 3 degrees cooler than normal as well. Despite the cooler weather lately, the entire state is still about 50 to 100 growing degree days ahead of average, going back to May 1st.
This week was also quite a bit drier, to much acclaim. 7-day rainfall ranged from less than a tenth of an inch in south-central Illinois to a little over 1 inch in far northwest Illinois. July to date has been the 4th wettest on record in St. Louis, 6th wettest in Chicago, and the 3rd wettest in the 117 year record in Danville. Following up on the severe weather from last week, the Chicago National Weather Service office has an unofficial count of 33 tornadoes from the evening of July 15th alone, along with more than a dozen additional tornadoes in other parts of the state that night. This event has pushed the unofficial 2024 tornado count ahead of all other years on record. The official tornado count will not be released until the beginning of next year, but given we have five months left of 2024, it is likely this year will be the most tornado active on record for the state.
Looking ahead, temperatures will remain on the mild side for the next couple of days, then begin to increase early next week. The combined effect of heat and humidity may push heat index values into the triple digits statewide next week, so the heat is going to be back on after a nice reprieve. The Climate Prediction Center’s outlook keeps above normal temperatures around for the month of August. Meanwhile, the next week looks to be a bit wetter for the eastern half of the state. 7-day forecasted totals range from less than a quarter of an inch for far western Illinois to maybe close to an inch for northeast Illinois. As the big ridge out west opens up, we expect the heat and maybe some dryness to start out August, especially for the western part of the state. However, outlooks for the month of August as a whole show equal chances of wetter and drier than normal conditions, indicating any dryness to start next month will not last long.