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.

Fair

71°F

22°C

Humidity 94%
Wind Speed S 5 mph
Barometer 29.83 in (1009.6 mb)
Dewpoint 69°F (21°C)
Visibility 9.00 mi
Last update 17 Jun 11:54 pm CDT
Extended Forecast for

Grafton IL

  • Overnight

    Overnight: Mostly cloudy, with a low around 73. Southeast wind around 8 mph becoming southwest.

    Low: 73 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 50 percent chance of showers and thunderstorms, mainly after 2pm. Some of the storms could produce heavy rainfall. Mostly cloudy, with a high near 83. Southwest wind 10 to 14 mph, with gusts as high as 25 mph.

    High: 83 °F

    Heavy Rain

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly before 9pm. Partly cloudy, with a low around 67. Southwest wind 6 to 10 mph becoming northwest after midnight.

    Low: 67 °F

    Chance
    T-storms then
    Partly Cloudy

  • Juneteenth

    Juneteenth: Sunny, with a high near 84. Northwest wind around 6 mph.

    High: 84 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 67. Light and variable wind.

    Low: 67 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 89.

    High: 89 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 74.

    Low: 74 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 93.

    High: 93 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 78.

    Low: 78 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly cloudy, with a low around 73. Southeast wind around 8 mph becoming southwest.
Wednesday
A 50 percent chance of showers and thunderstorms, mainly after 2pm. Some of the storms could produce heavy rainfall. Mostly cloudy, with a high near 83. Southwest wind 10 to 14 mph, with gusts as high as 25 mph.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly before 9pm. Partly cloudy, with a low around 67. Southwest wind 6 to 10 mph becoming northwest after midnight.
Juneteenth
Sunny, with a high near 84. Northwest wind around 6 mph.
Thursday Night
Mostly clear, with a low around 67. Light and variable wind.
Friday
Sunny, with a high near 89.
Friday Night
Mostly clear, with a low around 74.
Saturday
Sunny, with a high near 93.
Saturday Night
Mostly clear, with a low around 78.
Sunday
Sunny, with a high near 94.
Sunday Night
Mostly clear, with a low around 76.
Monday
Sunny, with a high near 93.
Monday Night
Mostly clear, with a low around 76.
Tuesday
A 20 percent chance of showers and thunderstorms. Sunny, with a high near 92.
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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:
10:52 pm CDT Jun 17, 2025
Forecast Valid:
12am CDT Jun 18, 2025-6pm CDT Jun 24, 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