Mount Vernon, IL 62864 Monthly Weather

Jefferson County1:43 PM CDT38.32°N, 88.91°W
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October 2026

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193°/70°0.02 inAvg 74°/50°
272°/58°0.11 inAvg 73°/50°
378°/49°Avg 73°/50°
482°/45°Avg 72°/49°
578°/44°Avg 72°/49°
680°/39°Avg 72°/48°
790°/42°Avg 71°/48°
887°/45°Avg 71°/48°
991°/43°Avg 70°/47°
1077°/49°Avg 70°/47°
1186°/53°Avg 70°/46°
1293°/53°Avg 69°/46°
1393°/59°Avg 69°/46°
1478°/66°0.17 inAvg 68°/45°
1582°/66°0.12 inAvg 68°/45°
1674°/51°<0.01 inAvg 68°/45°
1758°/41°Avg 67°/44°
1860°/33°<0.01 inAvg 67°/44°
19Avg 66°/44°
2072°/36°Avg 66°/43°
21 Sunny 75°/46°Avg 66°/43°
22 Patchy Fog then Sunny 77°/46°Avg 65°/42°
23 Sunny 75°/45°Avg 65°/42°
24 Mostly Sunny 75°/46°Avg 64°/42°
25 Mostly Sunny 77°/47°Avg 64°/41°
26 Partly Sunny 77°/48°Avg 63°/41°
27 Partly Sunny 73°/47°Avg 63°/41°
28 Partly cloudy 78°/53°Avg 62°/40°
29 Light showers 76°/53°Avg 62°/40°
30 Mostly sunny 63°/43°Avg 61°/40°
31Avg 61°/39°
Average high80° (normal 70°)
Average low50° (normal 47°)
Warmest / coldest93° / 33°
Precipitation0.43 in (normal 2.00 in to date)
Record high today88° (1963)
Record low today22° (1952)

Observed: Mt Vernon 3 Ne, 7 km away, records since 1895. 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.