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.

Overcast

82°F

28°C

Humidity 62%
Wind Speed SW 8 mph
Barometer 29.99 in
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index85°F (29°C)
Last update 24 Jun 5:50 pm CDT
Extended Forecast for

Alton ILSimilar City Names

Flood Watch June 25, 01:00pm until June 26, 07:00am
Click here for hazard details and duration
Flood Watch

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 67. Southwest wind around 5 mph becoming calm in the evening.

    Low: 67 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms, mainly after 11am. Partly sunny, with a high near 84. Calm wind becoming east around 5 mph in the afternoon.

    High: 84 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Some of the storms could produce heavy rainfall. Low around 68. Northeast wind around 5 mph becoming light and variable. Chance of precipitation is 80%.

    Low: 68 °F

    Heavy Rain

  • Friday

    Friday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 82. Southeast wind 6 to 8 mph becoming southwest in the afternoon. Chance of precipitation is 90%.

    High: 82 °F

    Heavy Rain

  • Friday Night

    Friday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 69. Southwest wind around 6 mph becoming light and variable after midnight. Chance of precipitation is 60%.

    Low: 69 °F

    Chance
    T-storms then
    Showers
    Likely

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 87.

    High: 87 °F

    Chance
    T-storms

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.

    Low: 74 °F

    Slight Chance
    T-storms

  • Sunday

    Sunday: Sunny, with a high near 95.

    High: 95 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 76.

    Low: 76 °F

    Mostly Clear

Detailed Forecast

Tonight
A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 67. Southwest wind around 5 mph becoming calm in the evening.
Thursday
A 40 percent chance of showers and thunderstorms, mainly after 11am. Partly sunny, with a high near 84. Calm wind becoming east around 5 mph in the afternoon.
Thursday Night
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1am. Some of the storms could produce heavy rainfall. Low around 68. Northeast wind around 5 mph becoming light and variable. Chance of precipitation is 80%.
Friday
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 82. Southeast wind 6 to 8 mph becoming southwest in the afternoon. Chance of precipitation is 90%.
Friday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 69. Southwest wind around 6 mph becoming light and variable after midnight. Chance of precipitation is 60%.
Saturday
A 40 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, with a high near 87.
Saturday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 74.
Sunday
Sunny, with a high near 95.
Sunday Night
Mostly clear, with a low around 76.
Monday
Sunny and hot, with a high near 97.
Monday Night
Mostly clear, with a low around 77.
Tuesday
Sunny and hot, with a high near 97.
Tuesday Night
Mostly clear, with a low around 77.
Wednesday
Sunny and hot, with a high near 97.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Alton ILSimilar City Names
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
5:41 pm CDT Jun 24, 2026
Forecast Valid:
6pm CDT Jun 24, 2026-6pm CDT Jul 1, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation