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

Hazardous Weather Conditions

Current conditions at

St. Louis Lambert International Airport (KSTL)

Lat: 38.75°NLon: 90.37°WElev: 604ft.

A Few Clouds

83°F

28°C

Humidity 65%
Wind Speed SW 6 mph
Barometer 30.07 in (1016.5 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 16 Aug 2:51 am CDT
Extended Forecast for

Saint Charles MO

Heat Advisory August 16, 03:04am until August 18, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 16, 03:04am until August 18, 08:00pm

    NOW until 8:00pm Mon

    Heat Advisory

  • Overnight

    Low: 76 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny and hot, with a high near 98. Heat index values as high as 106. Southwest wind around 6 mph.

    High: 98 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 77. Light and variable wind.

    Low: 77 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 98. Heat index values as high as 107. Light and variable wind.

    High: 98 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 78. Light south wind.

    Low: 78 °F

    Mostly Clear

  • Monday

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

    High: 98 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 77.

    Low: 77 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 96.

    High: 96 °F

    Sunny then
    Slight Chance
    T-storms

Detailed Forecast

Overnight
Mostly clear, with a low around 76. Light south wind.
Saturday
Sunny and hot, with a high near 98. Heat index values as high as 106. Southwest wind around 6 mph.
Saturday Night
Mostly clear, with a low around 77. Light and variable wind.
Sunday
Sunny and hot, with a high near 98. Heat index values as high as 107. Light and variable wind.
Sunday Night
Mostly clear, with a low around 78. Light south wind.
Monday
Sunny and hot, with a high near 98.
Monday Night
Mostly clear, with a low around 77.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 96.
Tuesday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 73.
Wednesday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 85.
Wednesday Night
Partly cloudy, with a low around 69.
Thursday
Mostly sunny, with a high near 84.
Thursday Night
Mostly clear, with a low around 67.
Friday
Sunny, with a high near 87.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Saint Charles MO
 38.81°N 90.54°W (Elev. 512 ft)
Last Update:
3:01 am CDT Aug 16, 2025
Forecast Valid:
3am CDT Aug 16, 2025-6pm CDT Aug 22, 2025
 
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