National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

St. Louis Regional Airport (KALN)

Lat: 38.89°NLon: 90.03°WElev: 518ft.

Mostly Cloudy

46°F

8°C

Humidity 87%
Wind Speed W 8 mph
Barometer 29.75 in
Dewpoint 43°F (6°C)
Visibility 10.00 mi
Wind Chill42°F (6°C)
Last update 14 Jan 12:35 am CST
Extended Forecast for

Alton IL

  • Overnight

    Overnight: Cloudy, with a low around 37. Northwest wind 6 to 14 mph, with gusts as high as 25 mph.

    Low: 37 °F

    Cloudy

  • Wednesday

    Wednesday: A chance of sprinkles and flurries before 8am, then a chance of flurries between 8am and 9am. Cloudy through mid morning, then gradual clearing, with a temperature falling to around 30 by 5pm. Breezy, with a northwest wind 16 to 22 mph, with gusts as high as 32 mph.

    High: 38 °F⇓

    Breezy.
    Chance
    Sprinkles/Flurries
    then Mostly
    Sunny

  • Wednesday Night

    Wednesday Night: Clear, with a low around 17. Northwest wind 8 to 15 mph, with gusts as high as 26 mph.

    Low: 17 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 33. Northwest wind 6 to 8 mph becoming south in the afternoon.

    High: 33 °F

    Sunny

  • Thursday Night

    Thursday Night: A 30 percent chance of snow. Mostly cloudy, with a low around 26. South wind 6 to 13 mph becoming west after midnight. Winds could gust as high as 21 mph.

    Low: 26 °F

    Chance Snow

  • Friday

    Friday: Partly sunny, with a high near 43. Breezy.

    High: 43 °F

    Mostly Sunny
    then Mostly
    Cloudy and
    Breezy

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 19.

    Low: 19 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 25.

    High: 25 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 10.

    Low: 10 °F

    Partly Cloudy

Detailed Forecast

Overnight
Cloudy, with a low around 37. Northwest wind 6 to 14 mph, with gusts as high as 25 mph.
Wednesday
A chance of sprinkles and flurries before 8am, then a chance of flurries between 8am and 9am. Cloudy through mid morning, then gradual clearing, with a temperature falling to around 30 by 5pm. Breezy, with a northwest wind 16 to 22 mph, with gusts as high as 32 mph.
Wednesday Night
Clear, with a low around 17. Northwest wind 8 to 15 mph, with gusts as high as 26 mph.
Thursday
Sunny, with a high near 33. Northwest wind 6 to 8 mph becoming south in the afternoon.
Thursday Night
A 30 percent chance of snow. Mostly cloudy, with a low around 26. South wind 6 to 13 mph becoming west after midnight. Winds could gust as high as 21 mph.
Friday
Partly sunny, with a high near 43. Breezy.
Friday Night
Mostly cloudy, with a low around 19.
Saturday
Partly sunny, with a high near 25.
Saturday Night
Partly cloudy, with a low around 10.
Sunday
Mostly sunny, with a high near 30.
Sunday Night
Partly cloudy, with a low around 16.
M.L.King Day
Sunny, with a high near 32.
Monday Night
Mostly clear, with a low around 11.
Tuesday
Mostly sunny, with a high near 30.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Alton IL
 38.91°N 90.13°W (Elev. 499 ft)
Last Update:
12:21 am CST Jan 14, 2026
Forecast Valid:
12am CST Jan 14, 2026-6pm CST Jan 20, 2026
 
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Additional Resources

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Chance of Precipitation