Dangerous Heat Index Values of 100 to 105 Degrees Arriving Across Illinois Including Peoria Springfield Quincy and Mt Vernon With Full Statewide Coverage Wednesday
ILLINOIS — Dangerous high heat and humidity is arriving across Illinois Tuesday with heat index values reaching 100 to 105 degrees across western and southern portions of the state, and the full overspread covering all of Illinois by Wednesday. The heat index map shows deep purple shading blanket the western and southern half of the state with values of 100 to 105 degrees, while the eastern corridor from Rockford through Chicago and Champaign sits in the 90 to 99 degree heat index range today.
Western Illinois is bearing the brunt of the initial heat surge with Quincy hitting 102, Peoria at 101, and Springfield reaching 100 degrees on the heat index map.
Western Illinois Seeing 100 to 102 Degree Heat Index Values Today
The most dangerous heat index readings Tuesday are concentrated across western Illinois, with Quincy leading at 102 degrees, Peoria at 101, and Springfield hitting 100. Moline is also running hot at 98 degrees as the initial surge of high heat and humidity pushes eastward across the state from the Missouri border.
St. Louis just across the border is showing a heat index of 105 degrees, indicating the intensity of the air mass positioned to the southwest that is driving these dangerous readings.
Southern Illinois Reaches 101 to 102 Degrees With Mt Vernon Marion and Paducah
Southern Illinois communities are also being hammered by dangerous heat, with Mt. Vernon reaching 101, Marion at 102, and Paducah hitting 102 degrees on the heat index map. These readings represent genuinely life-threatening conditions for anyone spending extended time outdoors without adequate hydration, shade, and rest breaks.
The 100 to 105 degree purple zone covers the western and southern Illinois footprint with no relief during the peak afternoon hours.
Full Statewide Heat Coverage Wednesday as Index Spreads to Chicago and Rockford
Chicago is currently sitting at a 91 degree heat index and Rockford at 90, but these readings will climb significantly Wednesday as the dangerous heat and humidity overspread the entire state. Outdoor workers and those without air conditioning across all of Illinois face the greatest risk through midweek.
Take heat precautions, stay hydrated, and never leave children or pets in vehicles. Stay with NapervilleLocal.com for the latest weather updates and local forecast coverage.
I’ve lived in Naperville long enough to see how quickly our community changes — from new developments downtown to sudden shifts in our Midwest weather. Reporting on Naperville news and daily forecasts gives me the chance to keep neighbors informed about what really matters. My goal is simple: deliver clear, timely updates so you always know what’s happening in our city and what to expect from the skies above.