Belleville, IL Monthly Weather

Saint Clair County3:44 PM CDT38.52°N, 89.98°WElevation 515 ft
← September

October 2026

Sun
Mon
Tue
Wed
Thu
Fri
Sat
192°/71°Avg 79°/51°
283°/65°0.18 inAvg 78°/51°
377°/51°Avg 78°/51°
482°/49°Avg 78°/50°
578°/53°Avg 77°/50°
680°/46°Avg 77°/50°
789°/49°Avg 76°/50°
886°/51°Avg 76°/49°
989°/50°Avg 76°/49°
1082°/52°Avg 75°/48°
1186°/50°Avg 75°/48°
1294°/59°Avg 74°/48°
1394°/62°Avg 74°/48°
1482°/71°0.38 inAvg 74°/47°
15Avg 73°/47°
16Avg 73°/47°
17Avg 72°/46°
18Avg 72°/46°
19Avg 72°/46°
20 Sunny 72°/48°Avg 71°/46°
21 Sunny 73°/48°Avg 71°/45°
22 Sunny 76°/49°Avg 70°/45°
23 Sunny 75°/49°Avg 70°/44°
24 Mostly Sunny 76°/52°Avg 69°/44°
25 Partly Sunny 78°/52°Avg 69°/44°
26 Partly Sunny 75°/49°Avg 68°/44°
27 Cloudy 61°/51°Avg 68°/43°
28 Mostly sunny 58°/43°Avg 67°/43°
29Avg 67°/43°
30Avg 66°/42°
31Avg 66°/42°
Average high85° (normal 76°)
Average low56° (normal 49°)
Warmest / coldest94° / 46°
Precipitation0.56 in (normal 1.21 in to date)
Record high today86° (2003)
Record low today23° (2022)

Observed: Belleville Siu Research, 13 km away, records since 1948. Normals 1991–2020. Climate data from NOAA's Regional Climate Centers (ACIS); recent days are preliminary. Days ahead: the forecast.

Forecasts, observations and alerts in the United States come from the National Weather Service (NOAA); radar from NOAA's Multi-Radar Multi-Sensor system; satellite imagery from NASA's Global Imagery Browse Services (GIBS) and NOAA's GOES satellites; the map from the U.S. Geological Survey's National Map; air quality from AirNow (EPA and its partners); hurricane information from the National Hurricane Center; climate normals and records from NOAA's Regional Climate Centers (ACIS). Forecasts outside the United States and the UV index: MET Norway (CC BY 4.0); observations outside the U.S.: airport reports via NOAA's Aviation Weather Center. Place names: GeoNames (CC BY 4.0). Data are copied on a schedule and may lag the sources; for warnings that affect your safety, follow your local National Weather Service office and emergency officials. Weather news is drawn from the 4Conservative index and reflects what the press published. Terms of use.