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

74°F

23°C

Humidity 94%
Wind Speed NE 3 mph
Barometer 30.01 in (1015.7 mb)
Dewpoint 72°F (22°C)
Visibility 8.00 mi
Last update 17 Aug 5:54 am CDT
Extended Forecast for

3 Miles WNW Hardin IL

Heat Advisory August 17, 06:15am until August 18, 08:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 17, 06:15am until August 18, 08:00pm

    NOW until 8:00pm Mon

    Heat Advisory

  • Today

    High: 96 °F

    Sunny then
    Slight Chance
    T-storms

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms before 9pm. Partly cloudy, with a low around 75. Calm wind.

    Low: 75 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Monday

    Monday: A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Sunny, with a high near 95. Heat index values as high as 107. Light south wind. Chance of precipitation is 20%.

    High: 95 °F

    Sunny then
    Slight Chance
    T-storms

  • Monday Night

    Monday Night: Partly cloudy, with a low around 74. Calm wind.

    Low: 74 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 91. Calm wind becoming west around 5 mph in the afternoon.

    High: 91 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 71.

    Low: 71 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A 20 percent chance of showers before 1pm. Partly sunny, with a high near 84.

    High: 84 °F

    Slight Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 66.

    Low: 66 °F

    Partly Cloudy

Detailed Forecast

Today
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 96. Heat index values as high as 107. Calm wind.
Tonight
A 20 percent chance of showers and thunderstorms before 9pm. Partly cloudy, with a low around 75. Calm wind.
Monday
A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Sunny, with a high near 95. Heat index values as high as 107. Light south wind. Chance of precipitation is 20%.
Monday Night
Partly cloudy, with a low around 74. Calm wind.
Tuesday
A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 91. Calm wind becoming west around 5 mph in the afternoon.
Tuesday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 71.
Wednesday
A 20 percent chance of showers before 1pm. Partly sunny, with a high near 84.
Wednesday Night
Partly cloudy, with a low around 66.
Thursday
Mostly sunny, with a high near 82.
Thursday Night
Mostly clear, with a low around 66.
Friday
Sunny, with a high near 86.
Friday Night
Mostly clear, with a low around 66.
Saturday
Sunny, with a high near 86.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles WNW Hardin IL
 39.16°N 90.69°W (Elev. 430 ft)
Last Update:
5:56 am CDT Aug 17, 2025
Forecast Valid:
6am CDT Aug 17, 2025-6pm CDT Aug 23, 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