textproduct: Central Illinois

KEY MESSAGES

- Record heat along with dry weather will prevail today and Tuesday with afternoon temperatures reaching the upper 80s to lower 90s.

- An active stretch of weather is expected Tuesday night through Thursday night with daily chances for showers and storms. There is a Marginal Risk for severe thunderstorms near the lower Illinois River Valley Tuesday night.

- Cooler air will arrive Friday into the weekend with highs dropping to the upper 50s and 60s and potential for frost Friday and Saturday nights as temperatures fall into the 30s.

DISCUSSION

Issued at 232 AM CDT Mon Oct 12 2026

Record Warmth through Tuesday... Record warmth is forecast through Tuesday as warm advection continues to build ridging over the area. Highs around 90 appear to be on track for today and Tuesday, which would set records for most sites across central and southeast IL.

Periods of precipitation Tuesday night through Thursday... A shortwave moving across the upper Midwest into southeast Canada Monday into Tuesday will push a cold front close to northern portions of the forecast area early Tuesday as it stalls out. Precipitation appears to be absent on this portion of the front in the absence of lift and a strong capping inversion near 850 mb through Tuesday afternoon. Tuesday evening, another disturbance tracking along the front, increasing moisture, and a low level jet developing to the west will initiate thunderstorm activity along the front, likely spreading into the area Tuesday night. Over 1000 J/kg MLCAPE and 40 kt deep layer shear to the west looks to accompany this system, with instability slowly waning as it moves east overnight. This should be sufficient for scattered severe storms and SPC continues to highlight a Marginal Risk for severe storms extending east into central IL to around I-55. Periods of precipitation look to continue Wednesday into Thursday as the front stalls across the region and additional disturbances propagate along the front. Precipitation looks to come to an end as a strong Canadian shortwave propagates toward the northeast U.S. Thursday night and pushes the front to the southeast. Total precipitation amounts are forecast to be around an inch Tuesday night through Thursday night, although much uncertainty continues due to the convective nature of precipitation. With recent dry conditions, overall the precipitation looks to be beneficial, but there is a Marginal Risk for excessive rainfall Wednesday and Thursday due to a threat of locally heavy rainfall.

Much cooler for the weekend... Cold air trailing the Canadian Trough will arrive Friday, and bring below normal temperatures through at least Sunday morning, although a strong rebound in temperatures looks to initiate on Sunday. Highs look to range from lower 70s to lower 80s Wednesday and Thursday with the front stalled near the area, cloud cover, and periods of precipitation. Friday into Saturday, model blend brings highs down to upper 50s and lower 60s. Lows Friday night and Saturday night are in the 30s bringing potential for frost as high pressure moves across the area bringing clear skies and light winds. Over the past day model ensembles have come into much better agreement with the overall pattern this weekend, however it should be noted that spread from 10th to 90th percentile temperatures is around 10 to 15 degrees through this period, so temperatures could easily vary 5 to 8 degrees from model blend forecast.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 555 AM CDT Mon Oct 12 2026

VFR conditions will continue through the forecast period, with periods of high clouds drifting over the region. Low level wind shear will develop after 02Z-06Z as SW winds at 2000 ft AGL around 40 kts spread over the area. Surface winds SSW 5-10 kts increasing to 10-15 kts with gusts around 20 kts by 18Z. Gusts decreasing after 00Z.

CLIMATE

Issued at 612 AM CDT Mon Oct 12 2026

Record high temperatures for today and Tuesday:

Location Monday Tuesday ======== ======= ======= Bloomington 88/1930 91/1899 Champaign 87/1962 86/1989 Charleston 89/1962 87/2017 Decatur 92/1962 90/1899 Jacksonville 88/1901 91/1899 Olney 89/1928 93/1928 Peoria 87/2024 88/1899 Springfield 89/1962 88/1975

Records for latest 90 degree high temperature for the year:

Location Date ======== ================ Bloomington October 15, 1899 Champaign October 14, 1899 Charleston October 15, 1897 Decatur October 15, 1938 Jacksonville October 30, 1950 Olney October 22, 1953 Peoria October 15, 1897 Springfield October 11, 1962

ILX WATCHES/WARNINGS/ADVISORIES

None.