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.

Fair

72°F

22°C

Humidity 87%
Wind Speed SW 3 mph
Barometer 29.98 in (1014.6 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Last update 24 Jun 11:53 pm CDT
Extended Forecast for

O'Fallon IL

Flood Watch June 25, 01:00pm until June 26, 07:00am
Click here for hazard details and duration
Flood Watch

  • Overnight

    Overnight: A 30 percent chance of showers, mainly after 3am. Partly cloudy, with a low around 68. Calm wind.

    Low: 68 °F

    Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers, then a chance of showers and thunderstorms after 10am. Partly sunny, with a high near 85. Light and variable wind. Chance of precipitation is 40%.

    High: 85 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 2am. Some of the storms could produce heavy rainfall. Low around 69. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 80%.

    Low: 69 °F

    Heavy Rain

  • Friday

    Friday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 83. Southwest wind 6 to 9 mph. Chance of precipitation is 90%.

    High: 83 °F

    Heavy Rain

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 70. Southwest wind 3 to 6 mph. Chance of precipitation is 60%.

    Low: 70 °F

    Showers
    Likely

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87.

    High: 87 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.

    Low: 74 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: Sunny, with a high near 95.

    High: 95 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 76.

    Low: 76 °F

    Mostly Clear

Detailed Forecast

Overnight
A 30 percent chance of showers, mainly after 3am. Partly cloudy, with a low around 68. Calm wind.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 10am. Partly sunny, with a high near 85. Light and variable wind. Chance of precipitation is 40%.
Thursday Night
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 2am. Some of the storms could produce heavy rainfall. Low around 69. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 80%.
Friday
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 83. Southwest wind 6 to 9 mph. Chance of precipitation is 90%.
Friday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 70. Southwest wind 3 to 6 mph. Chance of precipitation is 60%.
Saturday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 87.
Saturday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.
Sunday
Sunny, with a high near 95.
Sunday Night
Mostly clear, with a low around 76.
Monday
Sunny, with a high near 96.
Monday Night
Mostly clear, with a low around 77.
Tuesday
Sunny and hot, with a high near 97.
Tuesday Night
Clear, with a low around 77.
Wednesday
Sunny and hot, with a high near 97.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.92°W (Elev. 551 ft)
Last Update:
8:21 pm CDT Jun 24, 2026
Forecast Valid:
12am CDT Jun 25, 2026-6pm CDT Jul 1, 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