textproduct: Central Illinois

KEY MESSAGES

- A benign fall pattern will bring dry conditions, light winds, and pleasant temperatures this weekend and much of next week.

DISCUSSION

Issued at 141 PM CDT Fri Oct 2 2026

High pressure will build into the Great Lakes region tonight into Saturday, providing subsidence and cooler northeasterly flow for central IL to provide for mostly clear skies and seasonably cool temperatures. Lows tonight look to reach the mid 40s near and north of I-72 to around 50 south of I-70. Highs Saturday should be mainly in the lower 70s.

A minor uptick in temperatures is expected for Sunday as a shortwave passing by to the north pushes a weak cold front toward IL Sunday, disrupting the cool advection as winds turn southerly briefly. Models continue to keep all precipitation to the north of central IL with this feature. Lows Saturday night look to be up a few degrees over most of the area with upper 40s to around 50. Highs Sunday look to be around the mid to upper 70s.

Another expansive surface high moves into the Great Lakes region Monday and Tuesday and exits toward the Mid-Atlantic coast midweek. This will advect cooler air into central IL Monday and Tuesday for highs mainly in the lower 70s, then south to southwest flow behind the departing high will raise highs to near 80 for Wednesday through Friday. Under the influence of light winds and clear skies with the high pressure nearby, the coldest lows of the upcoming week are forecast for Monday night, with lower to mid 40s estimated at this time. No precipitation is forecast through the end of next week.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1219 AM CDT Sat Oct 3 2026 High pressure is centered over the Great Lakes tonight. Light winds under 10 kt will be in place through the period under the influence of this high, favoring a NE/ENE direction overnight, then veering slightly to the ESE/SE during the day Saturday. VFR conditions are expected through the period.

ILX WATCHES/WARNINGS/ADVISORIES

None.