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

Hazardous Weather Conditions

Current conditions at

St. Charles, St. Charles County Smartt Airport (KSET)

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Fair

95°F

35°C

Humidity 62%
Wind Speed W 5 mph
Barometer 29.89 in (1011.6 mb)
Dewpoint 80°F (27°C)
Visibility 10.00 mi
Heat Index115°F (46°C)
Last update 26 Jul 1:54 pm CDT
Extended Forecast for

2 Miles SSE Portage Des Sioux MO

Extreme Heat Warning July 26, 02:35pm until July 27, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning July 26, 02:35pm until July 27, 09:00pm

    NOW until 9:00pm Mon

    Extreme Heat Warning

  • This Afternoon

    High: 96 °F

    Isolated
    T-storms

  • Tonight

    Tonight: Isolated showers and thunderstorms before 9pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 78. Light and variable wind. Chance of precipitation is 20%.

    Low: 78 °F

    Isolated
    T-storms then
    Partly Cloudy

  • Monday

    Monday: Sunny and hot, with a high near 97. Heat index values as high as 111. Light and variable wind becoming southwest 6 to 11 mph in the morning.

    High: 97 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 79. Southwest wind 6 to 9 mph becoming west after midnight.

    Low: 79 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 92. North wind 6 to 11 mph.

    High: 92 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 70.

    Low: 70 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 88.

    High: 88 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 68.

    Low: 68 °F

    Mostly Clear

Detailed Forecast

This Afternoon
Isolated showers and thunderstorms after 3pm. Sunny, with a high near 96. Heat index values as high as 117. West wind around 6 mph. Chance of precipitation is 20%.
Tonight
Isolated showers and thunderstorms before 9pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 78. Light and variable wind. Chance of precipitation is 20%.
Monday
Sunny and hot, with a high near 97. Heat index values as high as 111. Light and variable wind becoming southwest 6 to 11 mph in the morning.
Monday Night
Mostly clear, with a low around 79. Southwest wind 6 to 9 mph becoming west after midnight.
Tuesday
Mostly sunny, with a high near 92. North wind 6 to 11 mph.
Tuesday Night
Mostly clear, with a low around 70.
Wednesday
Sunny, with a high near 88.
Wednesday Night
Mostly clear, with a low around 68.
Thursday
Sunny, with a high near 89.
Thursday Night
A 30 percent chance of showers after 1am. Mostly cloudy, with a low around 70.
Friday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 84.
Friday Night
A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 69.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 84.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles SSE Portage Des Sioux MO
 38.91°N 90.33°W (Elev. 427 ft)
Last Update:
2:26 pm CDT Jul 26, 2026
Forecast Valid:
2pm CDT Jul 26, 2026-6pm CDT Aug 1, 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