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

63°F

17°C

Humidity 96%
Wind Speed N 5 mph
Barometer 30.08 in
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Last update 22 Aug 6:15 am CDT
Extended Forecast for

Alton IL

  • Today

    Today: Patchy fog between 7am and 8am. Otherwise, sunny, with a high near 84. Calm wind becoming northeast around 5 mph in the afternoon.

    High: 84 °F

    Patchy Fog
    then Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 65. Light northeast wind.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: Increasing clouds, with a high near 85. Calm wind becoming northwest 5 to 8 mph in the afternoon.

    High: 85 °F

    Increasing
    Clouds

  • Saturday Night

    Saturday Night: Mostly cloudy, then gradually becoming clear, with a low around 58. North wind around 6 mph.

    Low: 58 °F

    Decreasing
    Clouds

  • Sunday

    Sunday: Sunny, with a high near 79. Northwest wind 5 to 10 mph.

    High: 79 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 57.

    Low: 57 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 75.

    High: 75 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 53.

    Low: 53 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 76.

    High: 76 °F

    Sunny

Detailed Forecast

Today
Patchy fog between 7am and 8am. Otherwise, sunny, with a high near 84. Calm wind becoming northeast around 5 mph in the afternoon.
Tonight
Mostly clear, with a low around 65. Light northeast wind.
Saturday
Increasing clouds, with a high near 85. Calm wind becoming northwest 5 to 8 mph in the afternoon.
Saturday Night
Mostly cloudy, then gradually becoming clear, with a low around 58. North wind around 6 mph.
Sunday
Sunny, with a high near 79. Northwest wind 5 to 10 mph.
Sunday Night
Mostly clear, with a low around 57.
Monday
Mostly sunny, with a high near 75.
Monday Night
Partly cloudy, with a low around 53.
Tuesday
Sunny, with a high near 76.
Tuesday Night
Mostly clear, with a low around 53.
Wednesday
Sunny, with a high near 77.
Wednesday Night
Partly cloudy, with a low around 56.
Thursday
Mostly sunny, with a high near 79.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.93°N 90.16°W (Elev. 505 ft)
Last Update:
5:41 am CDT Aug 22, 2025
Forecast Valid:
6am CDT Aug 22, 2025-6pm CDT Aug 28, 2025
 
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