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

41°F

5°C

Humidity 85%
Wind Speed Calm
Barometer 30.11 in
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Last update 9 Jan 11:35 pm CST
Extended Forecast for

Alton IL

  • Tonight

    Tonight: A 40 percent chance of rain, mainly after 4am. Mostly cloudy, with a low around 38. Calm wind becoming northwest around 6 mph after midnight.

    Low: 38 °F

    Chance Rain

  • Saturday

    Saturday: Rain likely, mainly before 10am. Cloudy through mid morning, then gradual clearing, with a high near 45. Northwest wind 8 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.

    High: 45 °F

    Rain Likely
    then Sunny

  • Saturday Night

    Saturday Night: A slight chance of rain before 9pm, then a slight chance of snow between 9pm and 10pm. Partly cloudy, with a low around 25. Northwest wind 10 to 15 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.

    Low: 25 °F

    Slight Chance
    Rain/Snow
    then Mostly
    Clear

  • Sunday

    Sunday: Sunny, with a high near 37. Northwest wind 6 to 15 mph, with gusts as high as 24 mph.

    High: 37 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 26. Southwest wind 3 to 7 mph.

    Low: 26 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 50.

    High: 50 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 36.

    Low: 36 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 55.

    High: 55 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 37.

    Low: 37 °F

    Mostly Cloudy

Detailed Forecast

Tonight
A 40 percent chance of rain, mainly after 4am. Mostly cloudy, with a low around 38. Calm wind becoming northwest around 6 mph after midnight.
Saturday
Rain likely, mainly before 10am. Cloudy through mid morning, then gradual clearing, with a high near 45. Northwest wind 8 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
Saturday Night
A slight chance of rain before 9pm, then a slight chance of snow between 9pm and 10pm. Partly cloudy, with a low around 25. Northwest wind 10 to 15 mph, with gusts as high as 29 mph. Chance of precipitation is 20%.
Sunday
Sunny, with a high near 37. Northwest wind 6 to 15 mph, with gusts as high as 24 mph.
Sunday Night
Mostly clear, with a low around 26. Southwest wind 3 to 7 mph.
Monday
Sunny, with a high near 50.
Monday Night
Partly cloudy, with a low around 36.
Tuesday
Partly sunny, with a high near 55.
Tuesday Night
Mostly cloudy, with a low around 37.
Wednesday
Mostly cloudy, with a high near 42.
Wednesday Night
Mostly cloudy, with a low around 22.
Thursday
Mostly sunny, with a high near 35.
Thursday Night
Partly cloudy, with a low around 26.
Friday
Mostly cloudy, with a high near 42.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
10:31 pm CST Jan 9, 2026
Forecast Valid:
11pm CST Jan 9, 2026-6pm CST Jan 16, 2026
 
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