textproduct: Central Illinois

KEY MESSAGES

- Relatively benign weather is on tap for the upcoming week, with the primary chance for any rain around mid week.

- Temperatures will not be out of the ordinary for this time of year, with high temperatures near 80 degrees Sunday and Monday creeping upward a bit through the week.

UPDATE

Issued at 838 PM CDT Sat Aug 22 2026

Spotty showers associated with an outflow boundary have all but come to an end as they reached along and south of I-70. The rest of the night will feature benign conditions as light northerly breezes continue. Cloud cover will be minimal as lows dip into the upper 50s to lower 60s. An unusually comfortable August night is in store.

DISCUSSION

Issued at 222 PM CDT Sat Aug 22 2026

Diurnal cumulus development has been increasing across the northern CWA early this afternoon. While surface CAPE's in that area are around 2000 J/kg, mid level lapse rates are fairly low. Between that and dew points only in the low-mid 60s, any precipitation this afternoon should mainly be in the form of sprinkles. The dry air will result in a couple of pleasant nights, with lows around 60 tonight and mid-upper 50s Sunday night.

The overall upper pattern over the next several days will favor a northwest flow into the Midwest, which will keep any significant heat or moisture surges at bay. The most interesting feature of note will be a shortwave diving southeast around mid week. With most of the available moisture near the Great Lakes, rain chances this far south will be more questionable, with 20-30% chances mainly centered on Wednesday night. Temperatures creep upward and are expected to reach the mid 80s by mid week, with enough moisture in place to get the heat index to around 90 in a few places.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 646 PM CDT Sat Aug 22 2026

Minimal impacts to aviation the next 24 hours. A gust front pushing through SPI in the next hour will create a wind shift to 030 with gusts to 18KT. Otherwise look for VFR conditions prevail the next 24 hours as northwest winds drop below 10kt toward sunset. A stray shower will pass DEC and could still bubble up near SPI early this eve. However, chances are quite low for wet travel surfaces at either airport. NW winds will continue tomorrow for the balance of the day in the 6 to 10KT range.

ILX WATCHES/WARNINGS/ADVISORIES

None.