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 Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

Partly Cloudy

94°F

34°C

Humidity 49%
Wind Speed SW 14 G 23 mph
Barometer 29.89 in (1010.6 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 11 Aug 5:51 pm CDT
Extended Forecast for

Florissant MO

Extreme Heat Warning August 11, 06:24pm until August 12, 08:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning August 11, 06:24pm until August 12, 08:00pm

    NOW until 8:00pm Wed

    Extreme Heat Warning

  • Tonight

    Low: 80 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Scattered showers and thunderstorms, mainly between 10am and 11am.  Mostly sunny and hot, with a high near 98. Heat index values as high as 109. Southwest wind around 8 mph.  Chance of precipitation is 30%.

    High: 98 °F

    Scattered
    T-storms

  • Wednesday Night

    Wednesday Night: Scattered showers and thunderstorms, mainly after 5am.  Partly cloudy, with a low around 79. South wind around 6 mph.  Chance of precipitation is 30%.

    Low: 79 °F

    Scattered
    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 107. East wind 5 to 7 mph becoming southwest 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 77. Southeast wind around 6 mph becoming northeast after midnight.

    Low: 77 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 96.

    High: 96 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 77.

    Low: 77 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny and hot, with a high near 99.

    High: 99 °F

    Hot

Detailed Forecast

Tonight
Partly cloudy, with a low around 80. South wind 6 to 8 mph.
Wednesday
Scattered showers and thunderstorms, mainly between 10am and 11am. Mostly sunny and hot, with a high near 98. Heat index values as high as 109. Southwest wind around 8 mph. Chance of precipitation is 30%.
Wednesday Night
Scattered showers and thunderstorms, mainly after 5am. Partly cloudy, with a low around 79. South wind around 6 mph. Chance of precipitation is 30%.
Thursday
Scattered showers and thunderstorms before 7am. Mostly sunny and hot, with a high near 97. Heat index values as high as 107. East wind 5 to 7 mph becoming southwest in the morning. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 77. Southeast wind around 6 mph becoming northeast after midnight.
Friday
Mostly sunny, with a high near 96.
Friday Night
Partly cloudy, with a low around 77.
Saturday
Mostly sunny and hot, with a high near 99.
Saturday Night
Mostly clear, with a low around 79.
Sunday
Sunny and hot, with a high near 98.
Sunday Night
Partly cloudy, with a low around 75.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 89.
Monday Night
Partly cloudy, with a low around 71.
Tuesday
Mostly sunny, with a high near 90.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
Florissant MO
 38.8°N 90.34°W (Elev. 499 ft)
5:06 pm CDT Aug 11, 2026
6pm CDT Aug 11, 2026-6pm CDT Aug 18, 2026
 
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Additional Resources

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Hourly Weather Forecast

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