National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

N/A

Humidity NA
Wind Speed NA
Barometer NA
Dewpoint N/A
Visibility NA
Last update *** Not a current observation ***
Extended Forecast for

O'Fallon IL

  • This Afternoon

    This Afternoon: Scattered showers, with thunderstorms also possible after 3pm. Cloudy, with a high near 54. Southeast wind around 5 mph becoming east. Chance of precipitation is 40%.

    High: 54 °F

    Scattered
    Showers

  • Tonight

    Tonight: Scattered showers and thunderstorms, then showers likely and possibly a thunderstorm after 3am. Patchy fog after 9pm. Otherwise, cloudy, with a low around 51. Northeast wind around 6 mph. Chance of precipitation is 70%.

    Low: 51 °F

    Showers
    Likely and
    Patchy Fog

  • Wednesday

    Wednesday: Showers and thunderstorms likely, then showers and possibly a thunderstorm after noon. Patchy fog before 10am. High near 65. Light and variable wind becoming southeast around 6 mph in the morning. Chance of precipitation is 90%.

    High: 65 °F

    Showers
    Likely and
    Patchy Fog
    then Showers

  • Wednesday Night

    Wednesday Night: Showers and possibly a thunderstorm. Low around 56. West wind around 6 mph becoming south in the evening. Chance of precipitation is 90%.

    Low: 56 °F

    Showers

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 70. Southwest wind 6 to 10 mph. Chance of precipitation is 70%.

    High: 70 °F

    Showers
    Likely then
    Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 57. Chance of precipitation is 50%.

    Low: 57 °F

    Chance
    Showers

  • Friday

    Friday: A chance of showers and thunderstorms before noon, then a slight chance of showers. Partly sunny, with a high near 78. Chance of precipitation is 40%.

    High: 78 °F

    Chance
    T-storms then
    Slight Chance
    Showers

  • Friday Night

    Friday Night: A chance of showers, then showers and possibly a thunderstorm after midnight. Low around 59. Chance of precipitation is 80%.

    Low: 59 °F

    Chance
    Showers then
    Showers

  • Saturday

    Saturday: Showers likely and possibly a thunderstorm before noon, then a slight chance of showers and thunderstorms after noon. Mostly cloudy, with a high near 69. Chance of precipitation is 70%.

    High: 69 °F

    Showers
    Likely then
    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
Scattered showers, with thunderstorms also possible after 3pm. Cloudy, with a high near 54. Southeast wind around 5 mph becoming east. Chance of precipitation is 40%.
Tonight
Scattered showers and thunderstorms, then showers likely and possibly a thunderstorm after 3am. Patchy fog after 9pm. Otherwise, cloudy, with a low around 51. Northeast wind around 6 mph. Chance of precipitation is 70%.
Wednesday
Showers and thunderstorms likely, then showers and possibly a thunderstorm after noon. Patchy fog before 10am. High near 65. Light and variable wind becoming southeast around 6 mph in the morning. Chance of precipitation is 90%.
Wednesday Night
Showers and possibly a thunderstorm. Low around 56. West wind around 6 mph becoming south in the evening. Chance of precipitation is 90%.
Thursday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 70. Southwest wind 6 to 10 mph. Chance of precipitation is 70%.
Thursday Night
A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 57. Chance of precipitation is 50%.
Friday
A chance of showers and thunderstorms before noon, then a slight chance of showers. Partly sunny, with a high near 78. Chance of precipitation is 40%.
Friday Night
A chance of showers, then showers and possibly a thunderstorm after midnight. Low around 59. Chance of precipitation is 80%.
Saturday
Showers likely and possibly a thunderstorm before noon, then a slight chance of showers and thunderstorms after noon. Mostly cloudy, with a high near 69. Chance of precipitation is 70%.
Saturday Night
Mostly cloudy, with a low around 44.
Sunday
Mostly sunny, with a high near 67.
Sunday Night
Partly cloudy, with a low around 50.
Monday
A 20 percent chance of showers. Sunny, with a high near 72.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.92°W (Elev. 551 ft)
Last Update:
10:46 am CST Mar 3, 2026
Forecast Valid:
12pm CST Mar 3, 2026-6pm CDT Mar 9, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation