Severe Thunderstorms and Heavy Rain Across the Ohio Valley;

Severe thunderstorms with damaging wind gusts will be possible from the mid-Mississippi Valley into parts of the Ohio Valley and central Appalachians. Heavy rain associated with these storms may lead to considerable flash and urban flooding impacts across portions of the Ohio Valley. Mid-summer heat persists from the Central Plains to the Southeast. Read More >

Current conditions at

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

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Fair

90°F

32°C

Humidity 63%
Wind Speed S 6 mph
Barometer 29.86 in (1010.2 mb)
Dewpoint 76°F (24°C)
Visibility 10.00 mi
Heat Index101°F (38°C)
Last update 11 Aug 6:54 pm CDT
Extended Forecast for

Lake St. Louis MO

Extreme Heat Warning August 11, 06:58pm until August 12, 08:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning August 11, 06:58pm until August 12, 08:00pm

    NOW until 8:00pm Wed

    Extreme Heat Warning

  • Tonight

    Low: 78 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Scattered showers and thunderstorms, mainly between 10am and 11am.  Mostly sunny and hot, with a high near 97. Heat index values as high as 110. Southwest wind 6 to 8 mph.  Chance of precipitation is 30%.

    High: 97 °F

    Scattered
    T-storms

  • Wednesday Night

    Wednesday Night: Isolated showers and thunderstorms.  Mostly clear, with a low around 76. South wind 3 to 5 mph.  Chance of precipitation is 20%.

    Low: 76 °F

    Isolated
    T-storms

  • Thursday

    Thursday: Scattered showers and thunderstorms before 7am.  Mostly sunny and hot, with a high near 97. Heat index values as high as 110. Light and variable wind becoming southeast around 5 mph in the morning.  Chance of precipitation is 30%.

    High: 97 °F

    Scattered
    T-storms then
    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 75. Southeast wind 3 to 5 mph.

    Low: 75 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 95.

    High: 95 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 75.

    Low: 75 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny and hot, with a high near 98.

    High: 98 °F

    Hot

Detailed Forecast

Tonight
Partly cloudy, with a low around 78. South wind 3 to 6 mph.
Wednesday
Scattered showers and thunderstorms, mainly between 10am and 11am. Mostly sunny and hot, with a high near 97. Heat index values as high as 110. Southwest wind 6 to 8 mph. Chance of precipitation is 30%.
Wednesday Night
Isolated showers and thunderstorms. Mostly clear, with a low around 76. South wind 3 to 5 mph. Chance of precipitation is 20%.
Thursday
Scattered showers and thunderstorms before 7am. Mostly sunny and hot, with a high near 97. Heat index values as high as 110. Light and variable wind becoming southeast around 5 mph in the morning. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 75. Southeast wind 3 to 5 mph.
Friday
Mostly sunny, with a high near 95.
Friday Night
Partly cloudy, with a low around 75.
Saturday
Sunny and hot, with a high near 98.
Saturday Night
Mostly clear, with a low around 76.
Sunday
Mostly sunny, with a high near 96.
Sunday Night
Partly cloudy, with a low around 73.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 88.
Monday Night
Partly cloudy, with a low around 69.
Tuesday
Mostly sunny, with a high near 89.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
Lake St. Louis MO
 38.79°N 90.79°W (Elev. 512 ft)
5:06 pm CDT Aug 11, 2026
6pm CDT Aug 11, 2026-6pm CDT Aug 18, 2026
 
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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