National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

St. Charles, St. Charles County Smartt Airport (KSET)

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Light Rain

73°F

23°C

Humidity 90%
Wind Speed Calm
Barometer 29.95 in (1013.6 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 25 Jun 8:54 pm CDT
Extended Forecast for

Grafton IL

Flood Watch June 25, 09:30pm until June 26, 07:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch June 25, 09:30pm until June 26, 07:00pm

    NOW until 7:00pm Fri

    Flood Watch

  • Tonight

    Low: 68 °F

    Showers

  • Friday

    Friday: Showers and possibly a thunderstorm, mainly before 1pm, then showers and thunderstorms likely after 1pm. High near 80. Southeast wind 8 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 90%.

    High: 80 °F

    Showers then
    T-storms
    Likely

  • Friday Night

    Friday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers after 4am. Mostly cloudy, with a low around 67. West wind 5 to 8 mph becoming light and variable after midnight. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    T-storms

  • Saturday

    Saturday: A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 84. Light and variable wind becoming south around 5 mph in the afternoon.

    High: 84 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Saturday Night

    Saturday Night: A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 71. Southeast wind around 7 mph.

    Low: 71 °F

    Chance
    T-storms

  • Sunday

    Sunday: Sunny, with a high near 94.

    High: 94 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 75.

    Low: 75 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 96.

    High: 96 °F

    Sunny

Detailed Forecast

Tonight
Showers and possibly a thunderstorm. Low around 68. Calm wind becoming southeast 5 to 8 mph after midnight. Chance of precipitation is 100%.
Friday
Showers and possibly a thunderstorm, mainly before 1pm, then showers and thunderstorms likely after 1pm. High near 80. Southeast wind 8 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 90%.
Friday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers after 4am. Mostly cloudy, with a low around 67. West wind 5 to 8 mph becoming light and variable after midnight. Chance of precipitation is 40%.
Saturday
A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 84. Light and variable wind becoming south around 5 mph in the afternoon.
Saturday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 71. Southeast wind around 7 mph.
Sunday
Sunny, with a high near 94.
Sunday Night
Mostly clear, with a low around 75.
Monday
Sunny, with a high near 96.
Monday Night
Mostly clear, with a low around 76.
Tuesday
Sunny and hot, with a high near 98.
Tuesday Night
Clear, with a low around 76.
Wednesday
Sunny and hot, with a high near 97.
Wednesday Night
Mostly clear, with a low around 76.
Thursday
Sunny, with a high near 96.
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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:
8:52 pm CDT Jun 25, 2026
Forecast Valid:
9pm CDT Jun 25, 2026-6pm CDT Jul 2, 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