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

42°F

6°C

Humidity 73%
Wind Speed E 8 mph
Barometer 30.26 in (1024.7 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Wind Chill37°F (3°C)
Last update 8 Apr 12:54 am CDT
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Overnight

    Overnight: Mostly cloudy, with a low around 41. Southeast wind around 9 mph.

    Low: 41 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 75. South wind 9 to 17 mph, with gusts as high as 30 mph.

    High: 75 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 56. South wind 8 to 14 mph.

    Low: 56 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 80. Southwest wind 7 to 10 mph.

    High: 80 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 30 percent chance of showers after 1am. Mostly cloudy, with a low around 59. South wind 6 to 9 mph.

    Low: 59 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 71. Chance of precipitation is 70%.

    High: 71 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 4am, then a chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 53. Chance of precipitation is 50%.

    Low: 53 °F

    Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: A chance of showers and thunderstorms before 7am, then a chance of showers between 7am and 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 73. Chance of precipitation is 30%.

    High: 73 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 59.

    Low: 59 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 41. Southeast wind around 9 mph.
Wednesday
Mostly sunny, with a high near 75. South wind 9 to 17 mph, with gusts as high as 30 mph.
Wednesday Night
Mostly clear, with a low around 56. South wind 8 to 14 mph.
Thursday
Mostly sunny, with a high near 80. Southwest wind 7 to 10 mph.
Thursday Night
A 30 percent chance of showers after 1am. Mostly cloudy, with a low around 59. South wind 6 to 9 mph.
Friday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 71. Chance of precipitation is 70%.
Friday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 4am, then a chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 53. Chance of precipitation is 50%.
Saturday
A chance of showers and thunderstorms before 7am, then a chance of showers between 7am and 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 73. Chance of precipitation is 30%.
Saturday Night
Partly cloudy, with a low around 59.
Sunday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 81.
Sunday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 65.
Monday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 83. Breezy.
Monday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 65. Chance of precipitation is 60%.
Tuesday
Showers and thunderstorms likely. Partly sunny, with a high near 81. Chance of precipitation is 60%.
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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:
1:25 am CDT Apr 8, 2026
Forecast Valid:
1am CDT Apr 8, 2026-6pm CDT Apr 14, 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