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

Hazardous Weather Conditions

Current conditions at

St. Louis, Spirit Of St. Louis Airport (KSUS)

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Fair

76°F

24°C

Humidity 94%
Wind Speed SE 3 mph
Barometer 29.88 in (1011.0 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 27 Jun 9:54 pm CDT
Extended Forecast for

O'Fallon MO

Extreme Heat Warning June 28, 12:00pm until July 3, 12:00am
Click here for hazard details and duration
Extreme Heat Warning

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly between 2am and 4am. Patchy fog after 2am. Otherwise, partly cloudy, with a low around 71. Light southeast wind.

    Low: 71 °F

    Chance
    T-storms and
    Patchy Fog

  • Sunday

    Sunday: Patchy fog before 8am. Otherwise, partly sunny, then gradually becoming sunny, with a high near 93. Heat index values as high as 105. South wind 5 to 8 mph.

    High: 93 °F

    Patchy Fog
    then Sunny

  • Sunday Night

    Sunday Night: Increasing clouds, with a low around 74. South wind 5 to 7 mph.

    Low: 74 °F

    Increasing
    Clouds

  • Monday

    Monday: Mostly sunny, with a high near 95. Heat index values as high as 107. South wind 6 to 9 mph.

    High: 95 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 75. South wind around 7 mph.

    Low: 75 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 96.

    High: 96 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Clear, with a low around 76.

    Low: 76 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 96.

    High: 96 °F

    Sunny

  • Wednesday Night

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

    Low: 76 °F

    Mostly Clear

Detailed Forecast

Tonight
A 30 percent chance of showers and thunderstorms, mainly between 2am and 4am. Patchy fog after 2am. Otherwise, partly cloudy, with a low around 71. Light southeast wind.
Sunday
Patchy fog before 8am. Otherwise, partly sunny, then gradually becoming sunny, with a high near 93. Heat index values as high as 105. South wind 5 to 8 mph.
Sunday Night
Increasing clouds, with a low around 74. South wind 5 to 7 mph.
Monday
Mostly sunny, with a high near 95. Heat index values as high as 107. South wind 6 to 9 mph.
Monday Night
Mostly clear, with a low around 75. South wind around 7 mph.
Tuesday
Sunny, with a high near 96.
Tuesday Night
Clear, with a low around 76.
Wednesday
Sunny, with a high near 96.
Wednesday Night
Mostly clear, with a low around 76.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 95.
Thursday Night
Partly cloudy, with a low around 75.
Friday
Sunny, with a high near 94.
Friday Night
A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 74.
Independence Day
A 20 percent chance of showers and thunderstorms. Sunny, with a high near 93.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon MO
 38.79°N 90.71°W (Elev. 535 ft)
Last Update:
9:11 pm CDT Jun 27, 2026
Forecast Valid:
10pm CDT Jun 27, 2026-6pm CDT Jul 4, 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