textproduct: Central Illinois

KEY MESSAGES

- Periods of heavy rain will spread across the area between Friday and Saturday. Slow-moving thunderstorms Friday night into Saturday morning will increase the risk for localized flash flooding over saturated ground. Total rainfall will average 1 to 2 inches across central Illinois, though localized spots could see 3 to 4+ inches where heavy rain bands repeat.

- Pleasant, dry conditions return Monday and Tuesday with high temperatures rebounding into the mid-80s.

LONG TERM

(Monday through Next Thursday)

Upper-level height rises and an amplifying western ridge will build back into the Great Lakes early next week, bringing a swift return to seasonably warm, dry, and pleasant summer conditions for Monday and Tuesday. Highs will rebound back into the mid-80s under mostly sunny skies.

The next opportunity for showers and thunderstorms arrives mid- week as a robust northern-stream shortwave drives a cold front toward the Upper Midwest. However, model guidance displays considerable spread regarding frontal penetration into central Illinois as the primary upper-level dynamics rapidly displace eastward into Canada. Will maintain lower-end rain chances (20%) for Wednesday into Thursday to account for lingering timing and boundary position uncertainties.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 638 PM CDT Thu Jul 30 2026

VFR flight rules and light winds are expected through the overnight hours as high pressure largely remains in control. Conditions are expected to deteriorate on Friday as an approaching low pressure system brings waves of showers and storms, low ceilings, and breezy south-southeast winds. Confidence is higher that widespread precipitation will lie north of I-74 closer to the center of the low with more scattered activity south of there. Ceilings will fall to at least MVFR category for most airfields, with a low chance (20- 40%) for IFR at KPIA and KBMI.

ILX WATCHES/WARNINGS/ADVISORIES

None.