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

Thunderstorms and Heavy Rainfall in the Southeast, Montana, and Iowa; Lowell Begins to Impact Hawaii

Strong thunderstorms with damaging winds and heavy rain are expected across portions of the Southeast. Thunderstorms may produce large hail across portions of Montana. Heavy rainfall could produce flash flooding across Iowa and vulnerable areas in Utah. Lowell will bring heavy rain, dangerous swells and rip currents to portions of Hawaii. Sweltering heat persists across the South-Central US. Read More >

Current conditions at

St. Louis Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

Mostly Cloudy

86°F

30°C

Humidity 45%
Wind Speed E 12 mph
Barometer 29.96 in (1013.4 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 6 Sep 6:51 pm CDT
Extended Forecast for

Florissant MO

  • Tonight

    Tonight: Partly cloudy, with a low around 64. East wind 6 to 10 mph.

    Low: 64 °F

    Partly Cloudy

  • Labor Day

    Labor Day: Sunny, with a high near 91. East wind 6 to 9 mph.

    High: 91 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 64. East wind 5 to 7 mph.

    Low: 64 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny and hot, with a high near 97. South wind 3 to 6 mph.

    High: 97 °F

    Hot

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 76. South wind 6 to 9 mph.

    Low: 76 °F

    Mostly Clear

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 98.

    High: 98 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Showers and possibly a thunderstorm. Low around 71. Chance of precipitation is 80%.

    Low: 71 °F

    Showers

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 86.

    High: 86 °F

    Chance
    Showers

  • Thursday Night

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

    Low: 65 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 64. East wind 6 to 10 mph.
Labor Day
Sunny, with a high near 91. East wind 6 to 9 mph.
Monday Night
Mostly clear, with a low around 64. East wind 5 to 7 mph.
Tuesday
Mostly sunny and hot, with a high near 97. South wind 3 to 6 mph.
Tuesday Night
Mostly clear, with a low around 76. South wind 6 to 9 mph.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 98.
Wednesday Night
Showers and possibly a thunderstorm. Low around 71. Chance of precipitation is 80%.
Thursday
A 40 percent chance of showers and thunderstorms before 1pm. Mostly cloudy, with a high near 86.
Thursday Night
Mostly clear, with a low around 65.
Friday
Sunny, with a high near 88.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly clear, with a low around 67.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 92.
Saturday Night
A 30 percent chance of showers and thunderstorms. Mostly clear, with a low around 70.
Sunday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 90.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Florissant MO
 38.8°N 90.34°W (Elev. 499 ft)
Last Update:
6:01 pm CDT Sep 6, 2026
Forecast Valid:
7pm CDT Sep 6, 2026-6pm CDT Sep 13, 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