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

73°F

23°C

Humidity 78%
Wind Speed E 6 mph
Barometer 30.01 in
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 15 Jun 7:50 pm CDT
Extended Forecast for

Alton IL

  • Tonight

    Tonight: Mostly cloudy, with a low around 70. East wind around 5 mph becoming calm in the evening.

    Low: 70 °F

    Mostly Cloudy

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms, mainly between 3pm and 4pm. Mostly cloudy, with a high near 84. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 84 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Monday Night

    Monday Night: Partly cloudy, with a low around 69. Southeast wind around 6 mph becoming calm in the evening.

    Low: 69 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 91. Calm wind becoming southwest around 6 mph in the afternoon.

    High: 91 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 73. South wind around 7 mph.

    Low: 73 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: Showers and thunderstorms likely, mainly after 1pm. Mostly cloudy, with a high near 88. Chance of precipitation is 60%.

    High: 88 °F

    Chance
    T-storms then
    T-storms
    Likely

  • Wednesday Night

    Wednesday Night: A 50 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 69.

    Low: 69 °F

    Chance
    T-storms

  • Juneteenth

    Juneteenth: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 67.

    Low: 67 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 70. East wind around 5 mph becoming calm in the evening.
Monday
A 30 percent chance of showers and thunderstorms, mainly between 3pm and 4pm. Mostly cloudy, with a high near 84. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
Partly cloudy, with a low around 69. Southeast wind around 6 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 91. Calm wind becoming southwest around 6 mph in the afternoon.
Tuesday Night
A 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 73. South wind around 7 mph.
Wednesday
Showers and thunderstorms likely, mainly after 1pm. Mostly cloudy, with a high near 88. Chance of precipitation is 60%.
Wednesday Night
A 50 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 69.
Juneteenth
Mostly sunny, with a high near 85.
Thursday Night
Mostly clear, with a low around 67.
Friday
Sunny, with a high near 89.
Friday Night
Mostly clear, with a low around 75.
Saturday
Sunny, with a high near 94.
Saturday Night
Mostly clear, with a low around 76.
Sunday
Sunny, with a high near 94.
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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:
5:51 pm CDT Jun 15, 2025
Forecast Valid:
8pm CDT Jun 15, 2025-6pm CDT Jun 22, 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