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

Areas of Dangerous Heat and Heavy Rain with Possible Flooding into this Weekend

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley into this weekend with heat advisories in effect. Heavy to excessive rainfall occurring at times through Sunday could bring areas of flooding to parts of the upper Midwest, central Great Lakes, southern New England and Virginia/North Carolina tidewater region. Read More >

Hazardous Weather Conditions

Current conditions at

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

Lat: 38.66°NLon: 90.66°WElev: 463ft.

Fair

79°F

26°C

Humidity 88%
Wind Speed Calm
Barometer 30.15 in (1019.9 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 17 Sep 9:54 pm CDT
Extended Forecast for

Ellisville MO

Heat Advisory September 17, 10:57pm until September 19, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory September 17, 10:57pm until September 19, 08:00pm

    NOW until 8:00pm Sat

    Heat Advisory

  • Tonight

    Low: 74 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 96. Heat index values as high as 105. Light and variable wind.

    High: 96 °F

    Sunny

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming clear, with a low around 74. Southeast wind 3 to 6 mph.

    Low: 74 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny through mid morning, then becoming mostly cloudy, with a high near 96. Heat index values as high as 100. Southwest wind 5 to 7 mph.

    High: 96 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 74. Calm wind becoming southwest around 5 mph after midnight.

    Low: 74 °F

    Partly Cloudy

  • Sunday

    Sunday: A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 93. Chance of precipitation is 20%.

    High: 93 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Sunday Night

    Sunday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 70.

    Low: 70 °F

    Chance
    T-storms

  • Monday

    Monday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.

    High: 82 °F

    Showers
    Likely

Detailed Forecast

Tonight
Mostly clear, with a low around 74. Calm wind.
Friday
Sunny, with a high near 96. Heat index values as high as 105. Light and variable wind.
Friday Night
Mostly cloudy, then gradually becoming clear, with a low around 74. Southeast wind 3 to 6 mph.
Saturday
Sunny through mid morning, then becoming mostly cloudy, with a high near 96. Heat index values as high as 100. Southwest wind 5 to 7 mph.
Saturday Night
Partly cloudy, with a low around 74. Calm wind becoming southwest around 5 mph after midnight.
Sunday
A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 93. Chance of precipitation is 20%.
Sunday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 70.
Monday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 82. Chance of precipitation is 60%.
Monday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 63.
Tuesday
Partly sunny, with a high near 75.
Tuesday Night
Partly cloudy, with a low around 59.
Wednesday
Mostly sunny, with a high near 77.
Wednesday Night
Partly cloudy, with a low around 61.
Thursday
Mostly sunny, with a high near 80.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Ellisville MO
 38.58°N 90.57°W (Elev. 696 ft)
Last Update:
9:46 pm CDT Sep 17, 2026
Forecast Valid:
10pm CDT Sep 17, 2026-6pm CDT Sep 24, 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