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

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

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Mostly Cloudy

42°F

6°C

Humidity 82%
Wind Speed SW 6 mph
Barometer 30.07 in (1018.4 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Wind Chill38°F (3°C)
Last update 7 Mar 11:54 pm CDT
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Tonight

    Tonight: Partly cloudy, with a low around 34. Southwest wind 3 to 5 mph.

    Low: 34 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 66. Light southwest wind increasing to 6 to 11 mph in the morning.

    High: 66 °F

    Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 45. South wind around 7 mph.

    Low: 45 °F

    Clear

  • Monday

    Monday: Sunny, with a high near 77. South wind 6 to 14 mph, with gusts as high as 21 mph.

    High: 77 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 59. South wind 6 to 9 mph.

    Low: 59 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms, mainly after noon. Partly sunny, with a high near 82.

    High: 82 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Showers and possibly a thunderstorm. Low around 50. Chance of precipitation is 90%.

    Low: 50 °F

    Showers

  • Wednesday

    Wednesday: Showers and possibly a thunderstorm before noon, then showers likely. High near 66. Chance of precipitation is 90%.

    High: 66 °F

    Showers then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers before midnight. Mostly clear, with a low around 32.

    Low: 32 °F

    Slight Chance
    Showers then
    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 34. Southwest wind 3 to 5 mph.
Sunday
Sunny, with a high near 66. Light southwest wind increasing to 6 to 11 mph in the morning.
Sunday Night
Clear, with a low around 45. South wind around 7 mph.
Monday
Sunny, with a high near 77. South wind 6 to 14 mph, with gusts as high as 21 mph.
Monday Night
Mostly clear, with a low around 59. South wind 6 to 9 mph.
Tuesday
A 50 percent chance of showers and thunderstorms, mainly after noon. Partly sunny, with a high near 82.
Tuesday Night
Showers and possibly a thunderstorm. Low around 50. Chance of precipitation is 90%.
Wednesday
Showers and possibly a thunderstorm before noon, then showers likely. High near 66. Chance of precipitation is 90%.
Wednesday Night
A 20 percent chance of showers before midnight. Mostly clear, with a low around 32.
Thursday
Sunny, with a high near 53.
Thursday Night
Mostly cloudy, with a low around 43.
Friday
Partly sunny, with a high near 67. Breezy.
Friday Night
Mostly cloudy, with a low around 38.
Saturday
Mostly cloudy, with a high near 56.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles E Portage Des Sioux MO
 38.93°N 90.27°W (Elev. 407 ft)
Last Update:
9:21 pm CST Mar 7, 2026
Forecast Valid:
11pm CST Mar 7, 2026-6pm CDT Mar 14, 2026
 
Forecast Discussion
 
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Additional Resources

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National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation