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

54°F

12°C

Humidity 72%
Wind Speed SE 6 mph
Barometer 30.14 in
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Wind Chill52°F (11°C)
Last update 14 May 7:45 am CDT
Extended Forecast for

Alton IL

  • Today

    Today: Sunny, with a high near 74. Southeast wind 3 to 8 mph.

    High: 74 °F

    Sunny

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 55. Southeast wind 9 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.

    Low: 55 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers and thunderstorms likely before 10am, then a slight chance of showers between 10am and 11am. Cloudy through mid morning, then gradual clearing, with a high near 81. South wind 13 to 15 mph, with gusts as high as 23 mph. Chance of precipitation is 60%.

    High: 81 °F

    Showers
    Likely then
    Mostly Sunny

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 64. South wind 7 to 10 mph.

    Low: 64 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Saturday

    Saturday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 83. Southwest wind 7 to 11 mph. Chance of precipitation is 70%.

    High: 83 °F

    Showers
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 64.

    Low: 64 °F

    Chance
    T-storms

  • Sunday

    Sunday: Mostly sunny, with a high near 89.

    High: 89 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 69.

    Low: 69 °F

    Mostly Clear

  • Monday

    Monday: A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. Breezy.

    High: 88 °F

    Breezy.
    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
Sunny, with a high near 74. Southeast wind 3 to 8 mph.
Tonight
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 5am. Increasing clouds, with a low around 55. Southeast wind 9 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Friday
Showers and thunderstorms likely before 10am, then a slight chance of showers between 10am and 11am. Cloudy through mid morning, then gradual clearing, with a high near 81. South wind 13 to 15 mph, with gusts as high as 23 mph. Chance of precipitation is 60%.
Friday Night
A 30 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 64. South wind 7 to 10 mph.
Saturday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 83. Southwest wind 7 to 11 mph. Chance of precipitation is 70%.
Saturday Night
A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 64.
Sunday
Mostly sunny, with a high near 89.
Sunday Night
Mostly clear, with a low around 69.
Monday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 88. Breezy.
Monday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 68. Chance of precipitation is 60%.
Tuesday
Showers and thunderstorms likely. Partly sunny, with a high near 81. Chance of precipitation is 70%.
Tuesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 61. Chance of precipitation is 70%.
Wednesday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 76.
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ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.93°N 90.16°W (Elev. 505 ft)
Last Update:
6:20 am CDT May 14, 2026
Forecast Valid:
8am CDT May 14, 2026-6pm CDT May 20, 2026
 
Forecast Discussion
 
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Additional Resources

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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