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

Strong Storms and Heavy Rainfall Threats; Dangerous Heat for Southern Plains into the Southwest

Thunderstorms, some severe, will impact areas of the Plains into the Midwest today. Rainfall can be locally heavy as well from these storms with isolated instances of flash flooding. Monsoonal flow will enhance rainfall across the Four Corners into the central Rockies today. Meanwhile, summer heat continues for the southern Plains, Southwest into southern California. Read More >

Current conditions at

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

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Fair

73°F

23°C

Humidity 71%
Wind Speed E 7 mph
Barometer 30.07 in (1017.7 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 25 Aug 8:54 am CDT
Extended Forecast for

O'Fallon MO

  • Today

    Today: Mostly sunny, with a high near 86. Light southeast wind.

    High: 86 °F

    Mostly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 69. Calm wind.

    Low: 69 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 89. Calm wind becoming west around 5 mph in the afternoon.

    High: 89 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 67. Light northwest wind.

    Low: 67 °F

    Decreasing
    Clouds

  • Thursday

    Thursday: Sunny, with a high near 85. Calm wind becoming north around 5 mph in the afternoon.

    High: 85 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 64.

    Low: 64 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 85.

    High: 85 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 86. Light southeast wind.
Tonight
Partly cloudy, with a low around 69. Calm wind.
Wednesday
Mostly sunny, with a high near 89. Calm wind becoming west around 5 mph in the afternoon.
Wednesday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 67. Light northwest wind.
Thursday
Sunny, with a high near 85. Calm wind becoming north around 5 mph in the afternoon.
Thursday Night
Mostly clear, with a low around 64.
Friday
Sunny, with a high near 85.
Friday Night
Mostly clear, with a low around 65.
Saturday
Mostly sunny, with a high near 88.
Saturday Night
Partly cloudy, with a low around 70.
Sunday
Mostly sunny, with a high near 93.
Sunday Night
Mostly clear, with a low around 74.
Monday
Mostly sunny, with a high near 94.
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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:
6:01 am CDT Aug 25, 2026
Forecast Valid:
9am CDT Aug 25, 2026-6pm CDT Aug 31, 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