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

28°F

-2°C

Humidity 80%
Wind Speed N 16 G 24 mph
Barometer 30.29 in
Dewpoint 23°F (-5°C)
Visibility 10.00 mi
Wind Chill16°F (-9°C)
Last update 7 Dec 8:50 pm CST
Extended Forecast for

Williamson IL

  • Tonight

    Tonight: Cloudy early, then gradual clearing, with a low around 19. North wind 6 to 13 mph, with gusts as high as 24 mph.

    Low: 19 °F

    Gradual
    Clearing

  • Monday

    Monday: Mostly sunny, with a high near 32. North wind around 6 mph becoming light and variable in the afternoon.

    High: 32 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 23. South wind 5 to 13 mph.

    Low: 23 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 49. Southwest wind 10 to 13 mph, with gusts as high as 20 mph.

    High: 49 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 37. South wind 11 to 16 mph becoming west after midnight. Winds could gust as high as 25 mph.

    Low: 37 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, with a temperature falling to around 36 by 5pm.

    High: 45 °F⇓

    Mostly Cloudy

  • Wednesday Night

    Wednesday Night: A 20 percent chance of snow after midnight. Mostly cloudy, with a low around 24.

    Low: 24 °F

    Mostly Cloudy
    then Slight
    Chance Snow

  • Thursday

    Thursday: A 40 percent chance of snow, mainly before noon. Mostly cloudy, with a high near 33.

    High: 33 °F

    Chance Snow

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 16.

    Low: 16 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Cloudy early, then gradual clearing, with a low around 19. North wind 6 to 13 mph, with gusts as high as 24 mph.
Monday
Mostly sunny, with a high near 32. North wind around 6 mph becoming light and variable in the afternoon.
Monday Night
Partly cloudy, with a low around 23. South wind 5 to 13 mph.
Tuesday
Mostly sunny, with a high near 49. Southwest wind 10 to 13 mph, with gusts as high as 20 mph.
Tuesday Night
Mostly cloudy, with a low around 37. South wind 11 to 16 mph becoming west after midnight. Winds could gust as high as 25 mph.
Wednesday
Mostly cloudy, with a temperature falling to around 36 by 5pm.
Wednesday Night
A 20 percent chance of snow after midnight. Mostly cloudy, with a low around 24.
Thursday
A 40 percent chance of snow, mainly before noon. Mostly cloudy, with a high near 33.
Thursday Night
Mostly cloudy, with a low around 16.
Friday
Partly sunny, with a high near 25.
Friday Night
Mostly cloudy, with a low around 3.
Saturday
Partly sunny and cold, with a high near 17.
Saturday Night
Mostly cloudy, with a low around 5.
Sunday
Mostly sunny, with a high near 23.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Williamson IL
 38.98°N 89.76°W (Elev. 597 ft)
Last Update:
6:51 pm CST Dec 7, 2025
Forecast Valid:
9pm CST Dec 7, 2025-6pm CST Dec 14, 2025
 
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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