Lincoln, Illinois – Anyone planning to spend time outdoors across central Illinois today should take precautions immediately as heat index values between 105 and 112 degrees create a dangerous combination of heat and humidity, with strong thunderstorms expected to develop late tonight and again Monday.
According to the National Weather Service in Lincoln, an Extreme Heat Warning remains in effect west of a line from Peoria to Taylorville through Monday, while much of the remainder of central Illinois is under a Heat Advisory. Peak heat index values are expected to reach 110 to 112 degrees around Springfield, Lincoln, Havana, Beardstown and Jacksonville, with readings between 105 and 109 degrees common elsewhere. Residents should avoid strenuous outdoor activities between 10 a.m. and 4 p.m., stay hydrated, wear lightweight clothing and take frequent breaks in air-conditioned spaces.
The weather pattern becomes more active after midnight tonight as isolated strong to severe thunderstorms move into portions of the region. Wind gusts up to 60 mph are the primary concern, although confidence remains lower west of Interstate 55.
Monday brings another round of dangerous heat before thunderstorms redevelop during the morning and again in the afternoon and evening. According to the Storm Prediction Center, eastern Illinois, including Bloomington, Champaign, Danville, Paris and surrounding communities, faces a Slight Risk (Level 2 of 5) for severe weather. Damaging straight-line winds will be the main hazard, with isolated large hail also possible. Forecasters note that the timing and intensity of Monday’s storms will depend on how overnight thunderstorms evolve.
Conditions begin to improve Tuesday as temperatures ease slightly into the upper 80s and lower 90s, with highs settling into the mid-80s by midweek. Additional thunderstorm chances remain in the forecast through the week, and more watches or warnings could be issued if severe weather develops.
Five-Day Forecast for Central Illinois
- Sunday: High 88–94°. Dangerous heat with heat index values up to 112°. Thunderstorms possible late.
- Monday: High 91–96°. Dangerous heat continues. Thunderstorms likely morning and again afternoon/evening.
- Tuesday: High 87–91°. Partly cloudy with a chance of thunderstorms.
- Wednesday: High 85–88°. Mostly sunny and less humid.
- Thursday: High 86–89°. Partly cloudy with another chance of thunderstorms.
