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

66°F

19°C

Humidity 34%
Wind Speed SE 8 mph
Barometer 30.19 in (1022.1 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Last update 20 Apr 4:54 pm CDT
Extended Forecast for

Dow IL

  • Tonight

    Tonight: Mostly clear, with a low around 49. Southeast wind around 9 mph.

    Low: 49 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 78. Southwest wind 10 to 18 mph, with gusts as high as 26 mph.

    High: 78 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 55. Southwest wind 10 to 14 mph, with gusts as high as 22 mph.

    Low: 55 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 77. Southwest wind 8 to 10 mph.

    High: 77 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 57. South wind 6 to 8 mph.

    Low: 57 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 81. Breezy.

    High: 81 °F

    Mostly Sunny
    then Mostly
    Sunny and
    Breezy

  • Thursday Night

    Thursday Night: A slight chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 60. Chance of precipitation is 70%.

    Low: 60 °F

    Slight Chance
    T-storms then
    Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 74. Chance of precipitation is 80%.

    High: 74 °F

    Showers

  • Friday Night

    Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 51. Chance of precipitation is 50%.

    Low: 51 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Mostly clear, with a low around 49. Southeast wind around 9 mph.
Tuesday
Sunny, with a high near 78. Southwest wind 10 to 18 mph, with gusts as high as 26 mph.
Tuesday Night
Mostly clear, with a low around 55. Southwest wind 10 to 14 mph, with gusts as high as 22 mph.
Wednesday
Sunny, with a high near 77. Southwest wind 8 to 10 mph.
Wednesday Night
Mostly clear, with a low around 57. South wind 6 to 8 mph.
Thursday
Mostly sunny, with a high near 81. Breezy.
Thursday Night
A slight chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 60. Chance of precipitation is 70%.
Friday
Showers and possibly a thunderstorm. High near 74. Chance of precipitation is 80%.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 51. Chance of precipitation is 50%.
Saturday
A 20 percent chance of showers. Mostly sunny, with a high near 71.
Saturday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 50.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 70.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 52.
Monday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Dow IL
 39.04°N 90.33°W (Elev. 623 ft)
Last Update:
2:56 pm CDT Apr 20, 2026
Forecast Valid:
5pm CDT Apr 20, 2026-6pm CDT Apr 27, 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