Springfield, Illinois – Oppressive heat will combine with increasing thunderstorm chances across central Illinois today, creating a day of dangerous heat followed by potentially strong storms late this afternoon and evening. Heat index values are expected to climb to 99 to 105 degrees before a cold front sparks scattered thunderstorms capable of heavy rain and gusty winds.
According to the National Weather Service in Lincoln, afternoon temperatures will reach 89 to 94 degrees, with humidity pushing feels-like temperatures above 100 degrees across much of the region. Thunderstorms are expected to develop later this afternoon and continue into the evening as the cold front moves south through central Illinois. Rain chances range from 40% to 60%, with the strongest storms capable of producing locally heavy rainfall and gusty winds.
The highest heat index values are forecast near 105 degrees around Springfield, while Peoria, Bloomington, Decatur, Champaign, Jacksonville, Beardstown, Galesburg, Lincoln, Effingham and Quincy are expected to experience heat index values between 101 and 104 degrees before storms develop.
Residents should stay hydrated, avoid prolonged outdoor activity during the hottest part of the day and monitor weather conditions if afternoon or evening plans take them outdoors. When thunderstorms approach, move indoors immediately and avoid flooded roadways during heavy downpours.
Conditions will become less humid on Sunday, with highs cooling into the lower to upper 80s under mostly sunny skies. Another round of scattered thunderstorms is expected to return Monday, with temperatures climbing back into the mid-80s to lower 90s before quieter weather arrives Tuesday.
Five-Day Forecast for Springfield, Illinois
- Today: High 89–94°. Heat index 99–105°. Scattered afternoon and evening thunderstorms (40–60%). Low 66–73°.
- Sunday: Mostly sunny. High 83–89°. Low 63–69°.
- Monday: Chance of showers and thunderstorms (40–60%). High 86–93°. Low 71–76°.
- Tuesday: Partly cloudy. High 86–92°. Low 61–67°.
