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

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Overcast

25°F

-4°C

Humidity 80%
Wind Speed S 10 mph
Barometer 30.11 in
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Wind Chill15°F (-9°C)
Last update 2 Dec 7:50 pm CST
Extended Forecast for

Glen Carbon IL

  • Tonight

    Tonight: Cloudy during the early evening, then gradual clearing, with a low around 17. South wind 3 to 6 mph.

    Low: 17 °F

    Gradual
    Clearing

  • Wednesday

    Wednesday: Increasing clouds, with a high near 39. South wind around 7 mph becoming northwest in the afternoon.

    High: 39 °F

    Increasing
    Clouds

  • Wednesday Night

    Wednesday Night: A 20 percent chance of snow after 9pm. Mostly cloudy, with a low around 14. North wind 6 to 11 mph.

    Low: 14 °F

    Slight Chance
    Snow

  • Thursday

    Thursday: Mostly sunny, with a high near 23. North wind 5 to 9 mph becoming light northeast in the afternoon.

    High: 23 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 11. Light and variable wind.

    Low: 11 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 36.

    High: 36 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 22.

    Low: 22 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 36.

    High: 36 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 24.

    Low: 24 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Cloudy during the early evening, then gradual clearing, with a low around 17. South wind 3 to 6 mph.
Wednesday
Increasing clouds, with a high near 39. South wind around 7 mph becoming northwest in the afternoon.
Wednesday Night
A 20 percent chance of snow after 9pm. Mostly cloudy, with a low around 14. North wind 6 to 11 mph.
Thursday
Mostly sunny, with a high near 23. North wind 5 to 9 mph becoming light northeast in the afternoon.
Thursday Night
Partly cloudy, with a low around 11. Light and variable wind.
Friday
Mostly sunny, with a high near 36.
Friday Night
Mostly cloudy, with a low around 22.
Saturday
Partly sunny, with a high near 36.
Saturday Night
Mostly cloudy, with a low around 24.
Sunday
A slight chance of rain and snow after noon. Mostly cloudy, with a high near 34. Chance of precipitation is 20%.
Sunday Night
Mostly cloudy, with a low around 18.
Monday
Partly sunny, with a high near 33.
Monday Night
A 20 percent chance of snow. Mostly cloudy, with a low around 26.
Tuesday
Partly sunny, with a high near 41.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Glen Carbon IL
 38.77°N 89.94°W (Elev. 564 ft)
Last Update:
8:31 pm CST Dec 2, 2025
Forecast Valid:
8pm CST Dec 2, 2025-6pm CST Dec 9, 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