National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Fair

88°F

31°C

Humidity 38%
Wind Speed S 8 mph
Barometer 30.16 in
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 3 Oct 3:50 pm CDT
Extended Forecast for

Alton ILSimilar City Names

  • Tonight

    Tonight: Mostly clear, with a low around 63. South wind 3 to 5 mph.

    Low: 63 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 86. Light south wind increasing to 5 to 10 mph in the morning.

    High: 86 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 59. South wind 5 to 8 mph.

    Low: 59 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 87. South wind 6 to 13 mph, with gusts as high as 21 mph.

    High: 87 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 64. South wind 5 to 8 mph.

    Low: 64 °F

    Mostly Clear

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 86.

    High: 86 °F

    Sunny then
    Slight Chance
    T-storms

  • Monday Night

    Monday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 63.

    Low: 63 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A 30 percent chance of showers, mainly before 1pm. Partly sunny, with a high near 80.

    High: 80 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 56.

    Low: 56 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 63. South wind 3 to 5 mph.
Saturday
Sunny, with a high near 86. Light south wind increasing to 5 to 10 mph in the morning.
Saturday Night
Clear, with a low around 59. South wind 5 to 8 mph.
Sunday
Sunny, with a high near 87. South wind 6 to 13 mph, with gusts as high as 21 mph.
Sunday Night
Mostly clear, with a low around 64. South wind 5 to 8 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 86.
Monday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 63.
Tuesday
A 30 percent chance of showers, mainly before 1pm. Partly sunny, with a high near 80.
Tuesday Night
Partly cloudy, with a low around 56.
Wednesday
Sunny, with a high near 76.
Wednesday Night
Mostly clear, with a low around 52.
Thursday
Sunny, with a high near 75.
Thursday Night
Mostly clear, with a low around 50.
Friday
Sunny, with a high near 79.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Alton ILSimilar City Names
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
4:16 pm CDT Oct 3, 2025
Forecast Valid:
4pm CDT Oct 3, 2025-6pm CDT Oct 10, 2025
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation