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.

A Few Clouds

93°F

34°C

Humidity 47%
Wind Speed SW 16 mph
Barometer 29.91 in
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index99°F (37°C)
Last update 21 Jun 5:50 pm CDT
Extended Forecast for

3 Miles WNW Alton IL

Extreme Heat Warning June 21, 05:54pm until June 24, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning June 21, 05:54pm until June 24, 09:00pm

    NOW until 9:00pm Tue

    Extreme Heat Warning

  • Tonight

    Low: 76 °F

    Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 97. Heat index values as high as 104. Southwest wind 8 to 13 mph, with gusts as high as 20 mph.

    High: 97 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 76. South wind 6 to 10 mph.

    Low: 76 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 96. Heat index values as high as 101. Southwest wind 6 to 8 mph.

    High: 96 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 75. South wind 3 to 8 mph.

    Low: 75 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 95.

    High: 95 °F

    Slight Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 75.

    Low: 75 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 93.

    High: 93 °F

    Sunny

Detailed Forecast

Tonight
Clear, with a low around 76. South wind 7 to 14 mph, with gusts as high as 22 mph.
Sunday
Sunny and hot, with a high near 97. Heat index values as high as 104. Southwest wind 8 to 13 mph, with gusts as high as 20 mph.
Sunday Night
Mostly clear, with a low around 76. South wind 6 to 10 mph.
Monday
Sunny, with a high near 96. Heat index values as high as 101. Southwest wind 6 to 8 mph.
Monday Night
Partly cloudy, with a low around 75. South wind 3 to 8 mph.
Tuesday
A 20 percent chance of showers and thunderstorms before 1pm. Mostly sunny, with a high near 95.
Tuesday Night
Partly cloudy, with a low around 75.
Wednesday
Sunny, with a high near 93.
Wednesday Night
Partly cloudy, with a low around 75.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 93.
Thursday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 74.
Friday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 92.
Friday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 91.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles WNW Alton IL
 38.93°N 90.19°W (Elev. 591 ft)
Last Update:
2:21 pm CDT Jun 21, 2025
Forecast Valid:
5pm CDT Jun 21, 2025-6pm CDT Jun 28, 2025
 
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