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.

Mostly Cloudy

67°F

19°C

Humidity 93%
Wind Speed NE 3 mph
Barometer 30.00 in (1015.6 mb)
Dewpoint 65°F (18°C)
Visibility 8.00 mi
Last update 15 Oct 5:54 am CDT
Extended Forecast for

Grafton IL

  • Today

    Today: Showers and thunderstorms before noon, then showers likely and possibly a thunderstorm between noon and 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 11am. High near 79. East wind 5 to 11 mph becoming southwest in the afternoon. Chance of precipitation is 90%.

    High: 79 °F

    Showers and
    Patchy Fog
    then Showers
    Likely

  • Tonight

    Tonight: Showers and thunderstorms likely before 1am, then isolated showers between 1am and 2am. Cloudy, then becoming partly cloudy toward daybreak, with a low around 48. Northwest wind 13 to 18 mph. Chance of precipitation is 70%.

    Low: 48 °F

    Showers
    Likely

  • Friday

    Friday: Partly sunny, with a high near 57. Breezy, with a northwest wind around 21 mph, with gusts as high as 31 mph.

    High: 57 °F

    Partly Sunny
    and Breezy

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 39. North wind 10 to 18 mph, with gusts as high as 26 mph.

    Low: 39 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 60. North wind 5 to 7 mph becoming calm in the afternoon.

    High: 60 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 38.

    Low: 38 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 42.

    Low: 42 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 72.

    High: 72 °F

    Mostly Sunny

Detailed Forecast

Today
Showers and thunderstorms before noon, then showers likely and possibly a thunderstorm between noon and 1pm, then a chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 11am. High near 79. East wind 5 to 11 mph becoming southwest in the afternoon. Chance of precipitation is 90%.
Tonight
Showers and thunderstorms likely before 1am, then isolated showers between 1am and 2am. Cloudy, then becoming partly cloudy toward daybreak, with a low around 48. Northwest wind 13 to 18 mph. Chance of precipitation is 70%.
Friday
Partly sunny, with a high near 57. Breezy, with a northwest wind around 21 mph, with gusts as high as 31 mph.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 39. North wind 10 to 18 mph, with gusts as high as 26 mph.
Saturday
Sunny, with a high near 60. North wind 5 to 7 mph becoming calm in the afternoon.
Saturday Night
Clear, with a low around 38.
Sunday
Sunny, with a high near 67.
Sunday Night
Mostly clear, with a low around 42.
Monday
Mostly sunny, with a high near 72.
Monday Night
Partly cloudy, with a low around 44.
Tuesday
Sunny, with a high near 74.
Tuesday Night
Mostly clear, with a low around 48.
Wednesday
Sunny, with a high near 77.
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ABOUT THIS FORECAST

 
Point Forecast:
Grafton IL
 38.98°N 90.42°W (Elev. 673 ft)
Last Update:
5:11 am CDT Oct 15, 2026
Forecast Valid:
6am CDT Oct 15, 2026-6pm CDT Oct 21, 2026
 
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Additional Resources

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Chance of Precipitation