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.

Mostly Cloudy

73°F

23°C

Humidity 83%
Wind Speed W 7 mph
Barometer 30.05 in
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Last update 14 Oct 11:50 am CDT
Extended Forecast for

Glen Carbon IL

  • This Afternoon

    This Afternoon: A 30 percent chance of showers, mainly before 4pm. Cloudy, with a high near 76. North wind around 5 mph.

    High: 76 °F

    Chance
    Showers

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly after 4am. Cloudy, with a low around 66. Calm wind becoming east around 5 mph after midnight.

    Low: 66 °F

    Cloudy then
    Chance
    Showers

  • Thursday

    Thursday: Showers and possibly a thunderstorm, mainly before noon, then a chance of showers and thunderstorms after noon. High near 83. East wind 5 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 80%.

    High: 83 °F

    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 1am, then a chance of showers between 1am and 4am. Mostly cloudy, with a low around 50. West wind 9 to 18 mph, with gusts as high as 28 mph. Chance of precipitation is 50%.

    Low: 50 °F

    Chance
    Showers

  • Friday

    Friday: A 20 percent chance of showers after 1pm. Mostly cloudy, with a high near 56. Breezy, with a northwest wind around 21 mph, with gusts as high as 31 mph.

    High: 56 °F

    Breezy.
    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Friday Night

    Friday Night: Partly cloudy, with a low around 40.

    Low: 40 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 61.

    High: 61 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 38.

    Low: 38 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

Detailed Forecast

This Afternoon
A 30 percent chance of showers, mainly before 4pm. Cloudy, with a high near 76. North wind around 5 mph.
Tonight
A 30 percent chance of showers and thunderstorms, mainly after 4am. Cloudy, with a low around 66. Calm wind becoming east around 5 mph after midnight.
Thursday
Showers and possibly a thunderstorm, mainly before noon, then a chance of showers and thunderstorms after noon. High near 83. East wind 5 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 80%.
Thursday Night
A chance of showers and thunderstorms before 1am, then a chance of showers between 1am and 4am. Mostly cloudy, with a low around 50. West wind 9 to 18 mph, with gusts as high as 28 mph. Chance of precipitation is 50%.
Friday
A 20 percent chance of showers after 1pm. Mostly cloudy, with a high near 56. Breezy, with a northwest wind around 21 mph, with gusts as high as 31 mph.
Friday Night
Partly cloudy, with a low around 40.
Saturday
Sunny, with a high near 61.
Saturday Night
Clear, with a low around 38.
Sunday
Sunny, with a high near 67.
Sunday Night
Mostly clear, with a low around 42.
Monday
Mostly sunny, with a high near 74.
Monday Night
Partly cloudy, with a low around 46.
Tuesday
Mostly sunny, with a high near 76.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Glen Carbon IL
 38.77°N 89.97°W (Elev. 548 ft)
Last Update:
2:06 pm CDT Oct 14, 2026
Forecast Valid:
2pm CDT Oct 14, 2026-6pm CDT Oct 20, 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