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.

Fair

51°F

11°C

Humidity 85%
Wind Speed Calm
Barometer 30.06 in
Dewpoint 46°F (8°C)
Visibility 10.00 mi
Last update 14 Nov 6:35 am CST
Extended Forecast for

Williamson IL

  • Today

    Today: Sunny, with a high near 75. Southwest wind 6 to 10 mph.

    High: 75 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 57. Southwest wind 7 to 10 mph.

    Low: 57 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 76. Southwest wind 10 to 14 mph becoming west in the afternoon. Winds could gust as high as 22 mph.

    High: 76 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 41. North wind 6 to 8 mph.

    Low: 41 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 59. North wind 5 to 7 mph.

    High: 59 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 36.

    Low: 36 °F

    Mostly Clear

  • Monday

    Monday: A 30 percent chance of rain after noon. Mostly sunny, with a high near 56.

    High: 56 °F

    Mostly Sunny
    then Chance
    Rain

  • Monday Night

    Monday Night: Rain likely. Mostly cloudy, with a low around 41. Chance of precipitation is 70%.

    Low: 41 °F

    Rain Likely

  • Tuesday

    Tuesday: A 20 percent chance of rain before noon. Partly sunny, with a high near 54.

    High: 54 °F

    Slight Chance
    Rain then
    Partly Sunny

Detailed Forecast

Today
Sunny, with a high near 75. Southwest wind 6 to 10 mph.
Tonight
Partly cloudy, with a low around 57. Southwest wind 7 to 10 mph.
Saturday
Partly sunny, with a high near 76. Southwest wind 10 to 14 mph becoming west in the afternoon. Winds could gust as high as 22 mph.
Saturday Night
Mostly clear, with a low around 41. North wind 6 to 8 mph.
Sunday
Sunny, with a high near 59. North wind 5 to 7 mph.
Sunday Night
Mostly clear, with a low around 36.
Monday
A 30 percent chance of rain after noon. Mostly sunny, with a high near 56.
Monday Night
Rain likely. Mostly cloudy, with a low around 41. Chance of precipitation is 70%.
Tuesday
A 20 percent chance of rain before noon. Partly sunny, with a high near 54.
Tuesday Night
A 20 percent chance of rain after midnight. Mostly cloudy, with a low around 35.
Wednesday
A 30 percent chance of rain. Partly sunny, with a high near 53.
Wednesday Night
Rain likely. Mostly cloudy, with a low around 40. Chance of precipitation is 60%.
Thursday
Rain likely. Mostly cloudy, with a high near 55. Chance of precipitation is 70%.
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ABOUT THIS FORECAST

 
Point Forecast:
Williamson IL
 38.98°N 89.76°W (Elev. 597 ft)
Last Update:
5:16 am CST Nov 14, 2025
Forecast Valid:
7am CST Nov 14, 2025-6pm CST Nov 20, 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