National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

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

Lat: 38.93°NLon: 90.43°WElev: 436ft.

Partly Cloudy

78°F

26°C

Humidity 79%
Wind Speed W 6 mph
Barometer 29.58 in (1000.9 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 17 Jun 11:54 pm CDT
Extended Forecast for

4 Miles W Grafton IL

  • Overnight

    Overnight: Partly cloudy, with a low around 68. West wind 6 to 8 mph.

    Low: 68 °F

    Partly Cloudy

  • Thursday

    Thursday: Increasing clouds, with a high near 78. Northwest wind 5 to 8 mph.

    High: 78 °F

    Increasing
    Clouds

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 60. Northwest wind around 5 mph becoming calm in the evening.

    Low: 60 °F

    Mostly Clear

  • Juneteenth

    Juneteenth: Mostly sunny, with a high near 83. Light northwest wind.

    High: 83 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 65. Light and variable wind.

    Low: 65 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 85.

    High: 85 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 67.

    Low: 67 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Sunday

    Sunday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 83. Chance of precipitation is 80%.

    High: 83 °F

    Heavy Rain

  • Sunday Night

    Sunday Night: Showers and possibly a thunderstorm before 1am, then a chance of showers. Low around 65. Chance of precipitation is 80%.

    Low: 65 °F

    Showers

Detailed Forecast

Overnight
Partly cloudy, with a low around 68. West wind 6 to 8 mph.
Thursday
Increasing clouds, with a high near 78. Northwest wind 5 to 8 mph.
Thursday Night
Mostly clear, with a low around 60. Northwest wind around 5 mph becoming calm in the evening.
Juneteenth
Mostly sunny, with a high near 83. Light northwest wind.
Friday Night
Partly cloudy, with a low around 65. Light and variable wind.
Saturday
Partly sunny, with a high near 85.
Saturday Night
A 50 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 67.
Sunday
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 83. Chance of precipitation is 80%.
Sunday Night
Showers and possibly a thunderstorm before 1am, then a chance of showers. Low around 65. Chance of precipitation is 80%.
Monday
Partly sunny, with a high near 79.
Monday Night
Partly cloudy, with a low around 61.
Tuesday
Mostly sunny, with a high near 81.
Tuesday Night
Partly cloudy, with a low around 63.
Wednesday
Mostly sunny, with a high near 83.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles W Grafton IL
 38.98°N 90.5°W (Elev. 620 ft)
Last Update:
10:31 pm CDT Jun 17, 2026
Forecast Valid:
12am CDT Jun 18, 2026-6pm CDT Jun 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