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

57°F

14°C

Humidity 94%
Wind Speed S 10 mph
Barometer 30.04 in
Dewpoint 55°F (13°C)
Visibility 8.00 mi
Last update 24 Dec 9:50 pm CST
Extended Forecast for

Alton IL

Dense Fog Advisory until December 25, 10:00am
Click here for hazard details and duration
Dense Fog Advisory
  •  
    Dense Fog Advisory until December 25, 10:00am

    NOW until 10:00am Thu

    Dense Fog Advisory

  • Tonight

    Low: 51 °F

    Patchy Dense
    Fog

  • Christmas Day

    Christmas Day: Areas of dense fog before noon. Otherwise, mostly cloudy, with a high near 66. Calm wind becoming east around 6 mph in the afternoon.

    High: 66 °F

    Areas Dense
    Fog then
    Mostly Cloudy

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 56. East wind around 6 mph becoming south after midnight.

    Low: 56 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 70. Southwest wind 6 to 10 mph becoming northwest in the afternoon.

    High: 70 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 46. Northwest wind around 5 mph becoming calm in the evening.

    Low: 46 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 67.

    High: 67 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 53.

    Low: 53 °F

    Mostly Cloudy

  • Sunday

    Sunday: A chance of rain and thunderstorms, then rain likely after noon. Cloudy, with a high near 59. Chance of precipitation is 60%.

    High: 59 °F

    Rain Likely

Detailed Forecast

Tonight
Patchy dense fog. Otherwise, increasing clouds, with a low around 51. Southwest wind around 5 mph becoming calm after midnight.
Christmas Day
Areas of dense fog before noon. Otherwise, mostly cloudy, with a high near 66. Calm wind becoming east around 6 mph in the afternoon.
Thursday Night
Mostly cloudy, with a low around 56. East wind around 6 mph becoming south after midnight.
Friday
Mostly sunny, with a high near 70. Southwest wind 6 to 10 mph becoming northwest in the afternoon.
Friday Night
Partly cloudy, with a low around 46. Northwest wind around 5 mph becoming calm in the evening.
Saturday
Partly sunny, with a high near 67.
Saturday Night
Mostly cloudy, with a low around 53.
Sunday
A chance of rain and thunderstorms, then rain likely after noon. Cloudy, with a high near 59. Chance of precipitation is 60%.
Sunday Night
A 20 percent chance of rain before midnight. Mostly cloudy, with a low around 20.
Monday
Sunny, with a high near 29.
Monday Night
Mostly clear, with a low around 18.
Tuesday
Mostly sunny, with a high near 35.
Tuesday Night
Mostly clear, with a low around 24.
Wednesday
Mostly sunny, with a high near 41.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.88°N 90.16°W (Elev. 466 ft)
Last Update:
9:31 pm CST Dec 24, 2025
Forecast Valid:
10pm CST Dec 24, 2025-6pm CST Dec 31, 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