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.

Partly Cloudy

73°F

23°C

Humidity 78%
Wind Speed SW 7 mph
Barometer 29.92 in
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 15 Oct 7:50 pm CDT
Extended Forecast for

Williamson IL

  • Tonight

    Tonight: Scattered showers, mainly before 1am. Increasing clouds, with a low around 47. Northwest wind 9 to 17 mph, with gusts as high as 26 mph. Chance of precipitation is 50%.

    Low: 47 °F

    Scattered
    Showers

  • Friday

    Friday: Isolated showers after 4pm. Mostly cloudy, with a high near 55. Breezy, with a northwest wind 18 to 21 mph, with gusts as high as 33 mph. Chance of precipitation is 20%.

    High: 55 °F

    Breezy.
    Partly Sunny
    then Isolated
    Showers

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 35. North wind 8 to 18 mph, with gusts as high as 28 mph.

    Low: 35 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 59. North wind around 6 mph becoming calm in the afternoon.

    High: 59 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 34. Calm wind.

    Low: 34 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 71.

    High: 71 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 41.

    Low: 41 °F

    Partly Cloudy

Detailed Forecast

Tonight
Scattered showers, mainly before 1am. Increasing clouds, with a low around 47. Northwest wind 9 to 17 mph, with gusts as high as 26 mph. Chance of precipitation is 50%.
Friday
Isolated showers after 4pm. Mostly cloudy, with a high near 55. Breezy, with a northwest wind 18 to 21 mph, with gusts as high as 33 mph. Chance of precipitation is 20%.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 35. North wind 8 to 18 mph, with gusts as high as 28 mph.
Saturday
Sunny, with a high near 59. North wind around 6 mph becoming calm in the afternoon.
Saturday Night
Clear, with a low around 34. Calm wind.
Sunday
Sunny, with a high near 67.
Sunday Night
Mostly clear, with a low around 37.
Monday
Mostly sunny, with a high near 71.
Monday Night
Partly cloudy, with a low around 41.
Tuesday
Mostly sunny, with a high near 76.
Tuesday Night
Mostly clear, with a low around 45.
Wednesday
Sunny, with a high near 79.
Wednesday Night
Mostly clear, with a low around 47.
Thursday
Sunny, with a high near 80.
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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:
7:46 pm CDT Oct 15, 2026
Forecast Valid:
8pm CDT Oct 15, 2026-6pm CDT Oct 22, 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