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

79°F

26°C

Humidity 73%
Wind Speed S 7 mph
Barometer 29.93 in
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 13 Oct 11:15 pm CDT
Extended Forecast for

Alton ILSimilar City Names

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 71. South wind 5 to 7 mph becoming west after midnight. Chance of precipitation is 60%.

    Low: 71 °F

    T-storms
    Likely

  • Wednesday

    Wednesday: Showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and noon, then a chance of showers and thunderstorms after noon. High near 78. West wind 5 to 7 mph becoming south in the morning. Chance of precipitation is 80%.

    High: 78 °F

    T-storms then
    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A slight chance of showers, then a chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 65. North wind 5 to 7 mph becoming east after midnight. Chance of precipitation is 30%.

    Low: 65 °F

    Chance
    T-storms

  • Thursday

    Thursday: Showers and thunderstorms, mainly before 3pm, then showers likely and possibly a thunderstorm after 5pm. Patchy fog between 10am and 11am. High near 82. East wind 6 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 80%.

    High: 82 °F

    Showers and
    Patchy Fog

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am. Mostly cloudy, with a low around 48. Northwest wind 9 to 18 mph, with gusts as high as 26 mph. Chance of precipitation is 60%.

    Low: 48 °F

    Showers
    Likely

  • Friday

    Friday: Mostly sunny, with a high near 61. Breezy.

    High: 61 °F

    Mostly Sunny
    and Breezy

  • Friday Night

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

    Low: 37 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 63.

    High: 63 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 39.

    Low: 39 °F

    Clear

Detailed Forecast

Tonight
Showers and thunderstorms likely, mainly after 5am. Increasing clouds, with a low around 71. South wind 5 to 7 mph becoming west after midnight. Chance of precipitation is 60%.
Wednesday
Showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and noon, then a chance of showers and thunderstorms after noon. High near 78. West wind 5 to 7 mph becoming south in the morning. Chance of precipitation is 80%.
Wednesday Night
A slight chance of showers, then a chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 65. North wind 5 to 7 mph becoming east after midnight. Chance of precipitation is 30%.
Thursday
Showers and thunderstorms, mainly before 3pm, then showers likely and possibly a thunderstorm after 5pm. Patchy fog between 10am and 11am. High near 82. East wind 6 to 10 mph becoming southwest in the afternoon. Chance of precipitation is 80%.
Thursday Night
Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am. Mostly cloudy, with a low around 48. Northwest wind 9 to 18 mph, with gusts as high as 26 mph. Chance of precipitation is 60%.
Friday
Mostly sunny, with a high near 61. Breezy.
Friday Night
Mostly clear, with a low around 37.
Saturday
Sunny, with a high near 63.
Saturday Night
Clear, with a low around 39.
Sunday
Sunny, with a high near 70.
Sunday Night
Partly cloudy, with a low around 46.
Monday
Mostly sunny, with a high near 73.
Monday Night
Partly cloudy, with a low around 49.
Tuesday
Mostly 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:
11:11 pm CDT Oct 13, 2026
Forecast Valid:
11pm CDT Oct 13, 2026-6pm CDT Oct 20, 2026
 
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Additional Resources

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Chance of Precipitation