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

21°F

-6°C

Humidity 54%
Wind Speed N 9 mph
Barometer 30.33 in
Dewpoint 7°F (-14°C)
Visibility 10.00 mi
Wind Chill11°F (-12°C)
Last update 4 Dec 2:50 pm CST
Extended Forecast for

Alton IL

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 22. North wind around 6 mph.

    High: 22 °F

    Partly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 6. Northeast wind around 5 mph becoming calm in the evening.

    Low: 6 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 36. Calm wind becoming south 5 to 7 mph in the morning.

    High: 36 °F

    Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 25. South wind around 6 mph becoming light and variable after midnight.

    Low: 25 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 35. Light and variable wind becoming east around 6 mph in the afternoon.

    High: 35 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of snow after midnight. Mostly cloudy, with a low around 27.

    Low: 27 °F

    Mostly Cloudy
    then Chance
    Snow

  • Sunday

    Sunday: A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 34. Chance of precipitation is 30%.

    High: 34 °F

    Chance
    Rain/Snow
    then Slight
    Chance Snow

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 13.

    Low: 13 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 30.

    High: 30 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Partly sunny, with a high near 22. North wind around 6 mph.
Tonight
Mostly clear, with a low around 6. Northeast wind around 5 mph becoming calm in the evening.
Friday
Sunny, with a high near 36. Calm wind becoming south 5 to 7 mph in the morning.
Friday Night
Mostly cloudy, with a low around 25. South wind around 6 mph becoming light and variable after midnight.
Saturday
Partly sunny, with a high near 35. Light and variable wind becoming east around 6 mph in the afternoon.
Saturday Night
A 30 percent chance of snow after midnight. Mostly cloudy, with a low around 27.
Sunday
A chance of rain and snow before noon, then a slight chance of snow. Mostly cloudy, with a high near 34. Chance of precipitation is 30%.
Sunday Night
Mostly cloudy, with a low around 13.
Monday
Mostly sunny, with a high near 30.
Monday Night
Partly cloudy, with a low around 22.
Tuesday
Mostly sunny, with a high near 42.
Tuesday Night
Mostly cloudy, with a low around 31.
Wednesday
A 30 percent chance of rain. Mostly cloudy, with a high near 44.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
1:26 pm CST Dec 4, 2025
Forecast Valid:
2pm CST Dec 4, 2025-6pm CST Dec 10, 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