O'Fallon, Illinois Weather
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Weather Forecast for O'Fallon, Illinois : St. Clair County
Issued: 2:21 am CDT Sep 16, 2025 Latitude: 38.5922715 Longitude: -89.9112124 View on Google Maps

MouseOver for Detail Forecast
Overnight Tuesday Wednesday Thursday Friday Saturday Sunday Monday
Mostly Clear on Overnight Sunny on Tuesday Sunny on Wednesday Mostly Sunny on Thursday 40% chance of thunderstorms on Friday 30% chance of thunderstorms on Saturday 30% chance of on Sunday 30% chance of thunderstorms on Monday
Low: 64°F High: 93°F High: 93°F High: 94°F High: 87°F High: 84°F High: 86°F High: 86°F
Low: 64°F Low: 63°F Low: 66°F Low: 65°F Low: 65°F Low: 66°F  
Mostly Clear Sunny Sunny Mostly Sunny Thunderstorms Thunderstorms Partly Sunny Thunderstorms
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Current Conditions at
SCOTT AFB - (KBLV)
70°
Clear
as of 2:55 AM CDST
Rel. Humidity: 88%
Dew Point: 66°F
Visibility: 10 Miles
Pressure: 30.08 in.
Flight Rule: VFR
Wind Data
Calm
Cloud Level(s): Clear
Current Conditions at
EAST ST LOUIS - (KCPS)
66°
Clear
as of 2:53 AM CDST
Rel. Humidity: 88%
Dew Point: 63°F
Visibility: 10 Miles
Pressure: 30.10 in.
Flight Rule: VFR
Wind Data
Calm
Cloud Level(s): Clear
Current Conditions at
ALTON - (KALN)
64°
Clear
as of 3:35 AM CDST
Rel. Humidity: 93%
Dew Point: 63°F
Visibility: 10 Miles
Pressure: 30.12 in.
Flight Rule: VFR
Wind Data
Calm
Cloud Level(s): Clear
Current Conditions at
ST LOUIS - (KSTL)
72°
Mostly Clear
as of 2:51 AM CDST
Rel. Humidity: 73%
Dew Point: 63°F
Visibility: 10 Miles
Pressure: 30.12 in.
Flight Rule: VFR
Wind Data
Calm
Cloud Level(s): Few at 25000ft
Mostly Clear on Overnight Overnight... Mostly clear, with a low around 64. Light and variable wind.
Sunny on Tuesday Tuesday... Sunny, with a high near 93. Northeast wind 3 to 7 mph.
Mostly Clear on Tuesday Night Tuesday Night... Mostly clear, with a low around 64. Northeast wind around 6 mph.
Sunny on Wednesday Wednesday... Sunny, with a high near 93. Calm wind becoming northeast around 5 mph in the afternoon.
Mostly Clear on Wednesday Night Wednesday Night... Mostly clear, with a low around 63. Light and variable wind.
Mostly Sunny on Thursday Thursday... Mostly sunny, with a high near 94.
20% chance of rain Thursday Night Thursday Night... A 20 percent chance of showers after 1am. Partly cloudy, with a low around 66.
40% chance of thunderstorms Friday Friday... A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 87. Chance of precipitation is 40%.
50% chance of thunderstorms Friday Night Friday Night... A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 65.
30% chance of thunderstorms Saturday Saturday... A chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 84. Chance of precipitation is 30%.
30% chance of thunderstorms Saturday Night Saturday Night... A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 65.
30% chance of Sunday Sunday... A 30 percent chance of showers. Partly sunny, with a high near 86.
40% chance of thunderstorms Sunday Night Sunday Night... A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
30% chance of thunderstorms Monday Monday... A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.
Current Radar Image


Sun Almanac for O'Fallon, Illinois
Sunrise: 06:43 AM
Sunset: 7:06 PM
Civil Sunrise:06:16 AM
Civil Sunset: 7:33 PM
Nautical Sunrise: 05:45 AM
Nautical Sunset: 8:04 PM
Astro Sunrise: 05:13 AM
Astro Sunset: 8:36 PM
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