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

21°F

-6°C

Humidity 50%
Wind Speed NE 6 mph
Barometer 30.37 in (1028.9 mb)
Dewpoint 5°F (-15°C)
Visibility 10.00 mi
Wind Chill13°F (-11°C)
Last update 4 Dec 12:54 pm CST
Extended Forecast for

Grafton IL

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 22. North wind around 6 mph.

    High: 22 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 7. Northeast wind around 5 mph becoming calm in the evening.

    Low: 7 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 36. South wind 5 to 8 mph.

    High: 36 °F

    Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 26. South wind around 6 mph becoming west after midnight.

    Low: 26 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 34. Light and variable wind becoming east around 6 mph in the afternoon.

    High: 34 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of snow after midnight. Mostly cloudy, with a low around 27.

    Low: 27 °F

    Mostly Cloudy
    then Chance
    Snow

  • Sunday

    Sunday: A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 33. Chance of precipitation is 30%.

    High: 33 °F

    Chance
    Rain/Snow
    then Slight
    Chance Snow

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 13.

    Low: 13 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 29.

    High: 29 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 22. North wind around 6 mph.
Tonight
Mostly clear, with a low around 7. Northeast wind around 5 mph becoming calm in the evening.
Friday
Sunny, with a high near 36. South wind 5 to 8 mph.
Friday Night
Mostly cloudy, with a low around 26. South wind around 6 mph becoming west after midnight.
Saturday
Partly sunny, with a high near 34. Light and variable wind becoming east around 6 mph in the afternoon.
Saturday Night
A 30 percent chance of snow after midnight. Mostly cloudy, with a low around 27.
Sunday
A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 33. Chance of precipitation is 30%.
Sunday Night
Mostly cloudy, with a low around 13.
Monday
Mostly sunny, with a high near 29.
Monday Night
Partly cloudy, with a low around 22.
Tuesday
Mostly sunny, with a high near 41.
Tuesday Night
Mostly cloudy, with a low around 32.
Wednesday
A 30 percent chance of rain. Mostly cloudy, with a high near 43.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grafton IL
 38.98°N 90.42°W (Elev. 673 ft)
Last Update:
1:26 pm CST Dec 4, 2025
Forecast Valid:
1pm CST Dec 4, 2025-6pm CST Dec 10, 2025
 
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