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

91°F

33°C

Humidity 57%
Wind Speed S 6 mph
Barometer 30.05 in (1017.1 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index100°F (38°C)
Last update 18 Aug 10:54 am CDT
Extended Forecast for

Hardin IL

Heat Advisory August 18, 11:02am until August 18, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 18, 11:02am until August 18, 08:00pm

    NOW until 8:00pm Mon

    Heat Advisory

  • Today

    High: 94 °F

    Sunny

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. South wind 3 to 5 mph.

    Low: 72 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91. Heat index values as high as 102. Calm wind becoming west around 5 mph in the afternoon.

    High: 91 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 4am, then a slight chance of showers. Partly cloudy, with a low around 72. Light north wind. Chance of precipitation is 30%.

    Low: 72 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 85. Northeast wind 5 to 8 mph. Chance of precipitation is 20%.

    High: 85 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Wednesday Night

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

    Low: 64 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 83.

    High: 83 °F

    Sunny

  • Thursday Night

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

    Low: 64 °F

    Mostly Clear

Detailed Forecast

Today
Sunny, with a high near 94. Heat index values as high as 107. South wind around 7 mph.
Tonight
A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 72. South wind 3 to 5 mph.
Tuesday
A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91. Heat index values as high as 102. Calm wind becoming west around 5 mph in the afternoon.
Tuesday Night
A chance of showers and thunderstorms before 4am, then a slight chance of showers. Partly cloudy, with a low around 72. Light north wind. Chance of precipitation is 30%.
Wednesday
A slight chance of showers, with thunderstorms also possible after 1pm. Mostly sunny, with a high near 85. Northeast wind 5 to 8 mph. Chance of precipitation is 20%.
Wednesday Night
Mostly clear, with a low around 64.
Thursday
Sunny, with a high near 83.
Thursday Night
Mostly clear, with a low around 64.
Friday
Sunny, with a high near 86.
Friday Night
Mostly clear, with a low around 65.
Saturday
Sunny, with a high near 85.
Saturday Night
Mostly clear, with a low around 61.
Sunday
Sunny, with a high near 80.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Hardin IL
 39.16°N 90.61°W (Elev. 427 ft)
Last Update:
10:21 am CDT Aug 18, 2025
Forecast Valid:
11am CDT Aug 18, 2025-6pm CDT Aug 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