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

62°F

17°C

Humidity 29%
Wind Speed W 7 mph
Barometer 29.85 in (1010.6 mb)
Dewpoint 29°F (-2°C)
Visibility 10.00 mi
Last update 27 Feb 6:54 pm CST
Extended Forecast for

4 Miles E Portage Des Sioux MO

  • Tonight

    Tonight: Clear, with a low around 36. West wind around 7 mph becoming northeast after midnight.

    Low: 36 °F

    Clear

  • Saturday

    Saturday: A slight chance of rain between 2pm and 5pm. Mostly sunny, with a high near 65. Northeast wind 6 to 10 mph becoming south in the afternoon. Chance of precipitation is 20%.

    High: 65 °F

    Sunny then
    Slight Chance
    Rain

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 29. Northeast wind 6 to 13 mph becoming south in the evening. Winds could gust as high as 21 mph.

    Low: 29 °F

    Partly Cloudy

  • Sunday

    Sunday: A slight chance of rain after noon, mixing with snow after 3pm. Mostly cloudy, with a high near 46. Northeast wind around 10 mph. Chance of precipitation is 20%.

    High: 46 °F

    Mostly Cloudy
    then Slight
    Chance
    Rain/Snow

  • Sunday Night

    Sunday Night: Rain and snow before 3am, then rain, snow, and freezing rain likely. Low around 32. East wind around 10 mph. Chance of precipitation is 80%. Little or no ice accumulation expected. New snow accumulation of less than one inch possible.

    Low: 32 °F

    Wintry Mix

  • Monday

    Monday: A chance of rain, snow, and freezing rain before noon, then a slight chance of rain. Cloudy, with a high near 44. Chance of precipitation is 40%.

    High: 44 °F

    Chance Wintry
    Mix then
    Slight Chance
    Rain

  • Monday Night

    Monday Night: Rain likely, mainly after midnight. Cloudy, with a low around 38. Chance of precipitation is 70%.

    Low: 38 °F

    Rain Likely

  • Tuesday

    Tuesday: Rain and possibly a thunderstorm. High near 57. Chance of precipitation is 80%.

    High: 57 °F

    Rain

  • Tuesday Night

    Tuesday Night: Rain likely, with thunderstorms also possible after midnight. Cloudy, with a low around 46. Chance of precipitation is 70%.

    Low: 46 °F

    Rain Likely

Detailed Forecast

Tonight
Clear, with a low around 36. West wind around 7 mph becoming northeast after midnight.
Saturday
A slight chance of rain between 2pm and 5pm. Mostly sunny, with a high near 65. Northeast wind 6 to 10 mph becoming south in the afternoon. Chance of precipitation is 20%.
Saturday Night
Partly cloudy, with a low around 29. Northeast wind 6 to 13 mph becoming south in the evening. Winds could gust as high as 21 mph.
Sunday
A slight chance of rain after noon, mixing with snow after 3pm. Mostly cloudy, with a high near 46. Northeast wind around 10 mph. Chance of precipitation is 20%.
Sunday Night
Rain and snow before 3am, then rain, snow, and freezing rain likely. Low around 32. East wind around 10 mph. Chance of precipitation is 80%. Little or no ice accumulation expected. New snow accumulation of less than one inch possible.
Monday
A chance of rain, snow, and freezing rain before noon, then a slight chance of rain. Cloudy, with a high near 44. Chance of precipitation is 40%.
Monday Night
Rain likely, mainly after midnight. Cloudy, with a low around 38. Chance of precipitation is 70%.
Tuesday
Rain and possibly a thunderstorm. High near 57. Chance of precipitation is 80%.
Tuesday Night
Rain likely, with thunderstorms also possible after midnight. Cloudy, with a low around 46. Chance of precipitation is 70%.
Wednesday
Rain likely and possibly a thunderstorm. Cloudy, with a high near 64. Chance of precipitation is 70%.
Wednesday Night
Rain likely. Mostly cloudy, with a low around 49. Chance of precipitation is 70%.
Thursday
Rain likely. Mostly cloudy, with a high near 66. Chance of precipitation is 60%.
Thursday Night
A 50 percent chance of rain and thunderstorms. Mostly cloudy, with a low around 52.
Friday
Rain likely and possibly a thunderstorm. Mostly cloudy, with a high near 70. Chance of precipitation is 60%.
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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:
5:06 pm CST Feb 27, 2026
Forecast Valid:
7pm CST Feb 27, 2026-6pm CST Mar 6, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation