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.

Fair

63°F

17°C

Humidity 63%
Wind Speed E 6 mph
Barometer 29.74 in (1006.8 mb)
Dewpoint 50°F (10°C)
Visibility 10.00 mi
Last update 21 Mar 9:54 pm CDT
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Tonight

    Tonight: Clear, with a low around 64. South wind around 7 mph.

    Low: 64 °F

    Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 87. Southwest wind 7 to 16 mph becoming north in the afternoon. Winds could gust as high as 23 mph.

    High: 87 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 38. Breezy, with a north wind 11 to 21 mph, with gusts as high as 33 mph.

    Low: 38 °F

    Partly Cloudy
    and Breezy
    then Mostly
    Clear

  • Monday

    Monday: Mostly sunny, with a high near 58. Northeast wind 8 to 10 mph.

    High: 58 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 41. Northeast wind around 6 mph.

    Low: 41 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 45.

    Low: 45 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 73.

    High: 73 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: A slight chance of rain and thunderstorms. Partly cloudy, with a low around 55. Chance of precipitation is 20%.

    Low: 55 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
Clear, with a low around 64. South wind around 7 mph.
Sunday
Mostly sunny, with a high near 87. Southwest wind 7 to 16 mph becoming north in the afternoon. Winds could gust as high as 23 mph.
Sunday Night
Partly cloudy, with a low around 38. Breezy, with a north wind 11 to 21 mph, with gusts as high as 33 mph.
Monday
Mostly sunny, with a high near 58. Northeast wind 8 to 10 mph.
Monday Night
Mostly cloudy, with a low around 41. Northeast wind around 6 mph.
Tuesday
Mostly sunny, with a high near 65.
Tuesday Night
Mostly cloudy, with a low around 45.
Wednesday
Partly sunny, with a high near 73.
Wednesday Night
A slight chance of rain and thunderstorms. Partly cloudy, with a low around 55. Chance of precipitation is 20%.
Thursday
A 20 percent chance of rain and thunderstorms after 1pm. Mostly sunny, with a high near 84.
Thursday Night
A 40 percent chance of rain and thunderstorms. Mostly cloudy, with a low around 45.
Friday
A 40 percent chance of rain. Partly sunny, with a high near 57.
Friday Night
A 20 percent chance of rain. Mostly cloudy, with a low around 37.
Saturday
A 20 percent chance of rain. Partly sunny, with a high near 57.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles E Portage Des Sioux MO
 38.93°N 90.27°W (Elev. 407 ft)
Last Update:
9:51 pm CDT Mar 21, 2026
Forecast Valid:
10pm CDT Mar 21, 2026-6pm CDT Mar 28, 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