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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.

Mostly Cloudy

76°F

24°C

Humidity 88%
Wind Speed Calm
Barometer 29.95 in (1013.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 9 Jun 5:54 am CDT
Extended Forecast for

Grafton IL

Heat Advisory June 9, 12:00pm until June 9, 10:00pm
Click here for hazard details and duration
Heat Advisory

  • Today

    Today: A 50 percent chance of showers and thunderstorms, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 90. Heat index values as high as 102. Southwest wind 5 to 8 mph.

    High: 90 °F

    Chance
    Showers then
    Slight Chance
    T-storms

  • Tonight

    Tonight: Mostly clear, with a low around 73. South wind 5 to 7 mph.

    Low: 73 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 93. Heat index values as high as 101. Southwest wind 8 to 13 mph, with gusts as high as 23 mph.

    High: 93 °F

    Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly clear, with a low around 75. South wind 9 to 11 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 93. Southwest wind 9 to 15 mph, with gusts as high as 25 mph.

    High: 93 °F

    Sunny then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm before 1am, then a slight chance of showers and thunderstorms after 1am. Low around 67. Chance of precipitation is 80%.

    Low: 67 °F

    Showers

  • Friday

    Friday: Sunny, with a high near 84.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 64.

    Low: 64 °F

    Mostly Clear

  • Saturday

    Saturday: A 20 percent chance of showers before 1pm. Mostly sunny, with a high near 87.

    High: 87 °F

    Slight Chance
    Showers

Detailed Forecast

Today
A 50 percent chance of showers and thunderstorms, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 90. Heat index values as high as 102. Southwest wind 5 to 8 mph.
Tonight
Mostly clear, with a low around 73. South wind 5 to 7 mph.
Wednesday
Sunny, with a high near 93. Heat index values as high as 101. Southwest wind 8 to 13 mph, with gusts as high as 23 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly clear, with a low around 75. South wind 9 to 11 mph, with gusts as high as 20 mph.
Thursday
A 40 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 93. Southwest wind 9 to 15 mph, with gusts as high as 25 mph.
Thursday Night
Showers and possibly a thunderstorm before 1am, then a slight chance of showers and thunderstorms after 1am. Low around 67. Chance of precipitation is 80%.
Friday
Sunny, with a high near 84.
Friday Night
Mostly clear, with a low around 64.
Saturday
A 20 percent chance of showers before 1pm. Mostly sunny, with a high near 87.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 67. Chance of precipitation is 50%.
Sunday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 82.
Sunday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 62.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 79.
Basemap Options
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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:
6:06 am CDT Jun 9, 2026
Forecast Valid:
6am CDT Jun 9, 2026-6pm CDT Jun 15, 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