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NWS St. Louis Announces Changes To May 16, 2025 Tornado Damage Assessment

After a year-long review of new ground survey data and aerial imagery, NWS St. Louis made several adjustments to the May 16, 2025 tornado damage assessment. Read More >

Hazardous Weather Conditions

Current conditions at

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

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Fair

82°F

28°C

Humidity 53%
Wind Speed S 12 mph
Barometer 29.81 in (1008.9 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 17 May 7:54 pm CDT
Extended Forecast for

Grafton IL

  • Tonight

    Tonight: Increasing clouds, with a low around 71. South wind 13 to 15 mph, with gusts as high as 25 mph.

    Low: 71 °F

    Increasing
    Clouds

  • Monday

    Monday: Showers and thunderstorms likely, mainly between 10am and 2pm. Mostly cloudy, with a high near 85. South wind 13 to 15 mph, with gusts as high as 26 mph. Chance of precipitation is 70%.

    High: 85 °F

    T-storms
    Likely

  • Monday Night

    Monday Night: Showers and thunderstorms likely, mainly after 4am. Mostly cloudy, then gradually becoming mostly clear, with a low around 69. South wind 13 to 15 mph, with gusts as high as 24 mph. Chance of precipitation is 60%.

    Low: 69 °F

    Slight Chance
    T-storms then
    T-storms
    Likely

  • Tuesday

    Tuesday: Showers and thunderstorms. High near 83. South wind 10 to 13 mph becoming west in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 90%.

    High: 83 °F

    T-storms

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 55. Northwest wind 8 to 10 mph.

    Low: 55 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Partly sunny, with a high near 68.

    High: 68 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 50.

    Low: 50 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 71.

    High: 71 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 55.

    Low: 55 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

Detailed Forecast

Tonight
Increasing clouds, with a low around 71. South wind 13 to 15 mph, with gusts as high as 25 mph.
Monday
Showers and thunderstorms likely, mainly between 10am and 2pm. Mostly cloudy, with a high near 85. South wind 13 to 15 mph, with gusts as high as 26 mph. Chance of precipitation is 70%.
Monday Night
Showers and thunderstorms likely, mainly after 4am. Mostly cloudy, then gradually becoming mostly clear, with a low around 69. South wind 13 to 15 mph, with gusts as high as 24 mph. Chance of precipitation is 60%.
Tuesday
Showers and thunderstorms. High near 83. South wind 10 to 13 mph becoming west in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 90%.
Tuesday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 55. Northwest wind 8 to 10 mph.
Wednesday
Partly sunny, with a high near 68.
Wednesday Night
Mostly cloudy, with a low around 50.
Thursday
Mostly sunny, with a high near 71.
Thursday Night
A 20 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 55.
Friday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 75.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 58.
Saturday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 81.
Saturday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 61.
Sunday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Grafton IL
 38.98°N 90.44°W (Elev. 515 ft)
Last Update:
5:16 pm CDT May 17, 2026
Forecast Valid:
8pm CDT May 17, 2026-6pm CDT May 24, 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