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

55°F

13°C

Humidity 37%
Wind Speed SE 9 mph
Barometer 30.15 in (1021.0 mb)
Dewpoint 29°F (-2°C)
Visibility 10.00 mi
Wind Chill53°F (12°C)
Last update 24 Mar 11:54 pm CDT
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Overnight

    Overnight: Mostly cloudy, with a low around 43. Southeast wind around 6 mph.

    Low: 43 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 79. Light and variable wind becoming south 6 to 11 mph in the morning.

    High: 79 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, then gradually becoming clear, with a low around 64. South wind around 10 mph.

    Low: 64 °F

    Decreasing
    Clouds

  • Thursday

    Thursday: A 20 percent chance of rain after 1pm. Increasing clouds, with a high near 91. Southwest wind 9 to 15 mph, with gusts as high as 24 mph.

    High: 91 °F

    Sunny then
    Slight Chance
    Rain

  • Thursday Night

    Thursday Night: Rain. Low around 43. Southwest wind 10 to 17 mph becoming north after midnight. Winds could gust as high as 26 mph. Chance of precipitation is 90%.

    Low: 43 °F

    Rain

  • Friday

    Friday: A 30 percent chance of rain before 1pm. Partly sunny, with a high near 53.

    High: 53 °F

    Chance Rain

  • Friday Night

    Friday Night: Mostly clear, with a low around 31.

    Low: 31 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 59.

    High: 59 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 40.

    Low: 40 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 43. Southeast wind around 6 mph.
Wednesday
Mostly sunny, with a high near 79. Light and variable wind becoming south 6 to 11 mph in the morning.
Wednesday Night
Mostly cloudy, then gradually becoming clear, with a low around 64. South wind around 10 mph.
Thursday
A 20 percent chance of rain after 1pm. Increasing clouds, with a high near 91. Southwest wind 9 to 15 mph, with gusts as high as 24 mph.
Thursday Night
Rain. Low around 43. Southwest wind 10 to 17 mph becoming north after midnight. Winds could gust as high as 26 mph. Chance of precipitation is 90%.
Friday
A 30 percent chance of rain before 1pm. Partly sunny, with a high near 53.
Friday Night
Mostly clear, with a low around 31.
Saturday
Sunny, with a high near 59.
Saturday Night
Partly cloudy, with a low around 40.
Sunday
Partly sunny, with a high near 65.
Sunday Night
Mostly cloudy, with a low around 49.
Monday
Mostly sunny, with a high near 80.
Monday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 58.
Tuesday
A 40 percent chance of rain and thunderstorms. Partly sunny, with a high near 78.
Basemap Options
Click map to change the forecast location
Loading map...
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:
12:06 am CDT Mar 25, 2026
Forecast Valid:
12am CDT Mar 25, 2026-6pm CDT Mar 31, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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