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

67°F

19°C

Humidity 90%
Wind Speed S 3 mph
Barometer 30.03 in
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 20 Jun 6:15 am CDT
Extended Forecast for

Alton IL

Extreme Heat Watch June 21, 12:00pm until June 24, 09:00pm
Click here for hazard details and duration
Extreme Heat Watch

  • Today

    Today: Mostly sunny, with a high near 93. Light and variable wind becoming south 6 to 11 mph in the morning.

    High: 93 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 76. South wind 9 to 13 mph.

    Low: 76 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 96. Heat index values as high as 104. South wind 10 to 14 mph, with gusts as high as 23 mph.

    High: 96 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 77. South wind 7 to 10 mph.

    Low: 77 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 96. Southwest wind 7 to 10 mph.

    High: 96 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 77.

    Low: 77 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 95.

    High: 95 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 76.

    Low: 76 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers before 1pm. Mostly sunny, with a high near 94.

    High: 94 °F

    Slight Chance
    Showers

Detailed Forecast

Today
Mostly sunny, with a high near 93. Light and variable wind becoming south 6 to 11 mph in the morning.
Tonight
Mostly clear, with a low around 76. South wind 9 to 13 mph.
Saturday
Sunny, with a high near 96. Heat index values as high as 104. South wind 10 to 14 mph, with gusts as high as 23 mph.
Saturday Night
Mostly clear, with a low around 77. South wind 7 to 10 mph.
Sunday
Sunny, with a high near 96. Southwest wind 7 to 10 mph.
Sunday Night
Mostly clear, with a low around 77.
Monday
Sunny, with a high near 95.
Monday Night
Partly cloudy, with a low around 76.
Tuesday
A 20 percent chance of showers before 1pm. Mostly sunny, with a high near 94.
Tuesday Night
Partly cloudy, with a low around 76.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 94.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
5:37 am CDT Jun 20, 2025
Forecast Valid:
6am CDT Jun 20, 2025-6pm CDT Jun 26, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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