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.

Mostly Cloudy

79°F

26°C

Humidity 84%
Wind Speed N 8 mph
Barometer 30.01 in
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 13 Jul 2:50 pm CDT
Extended Forecast for

Alton ILSimilar City Names

  • This Afternoon

    This Afternoon: Showers and thunderstorms likely, mainly before 5pm. Cloudy, with a steady temperature around 77. Light and variable wind becoming northeast around 5 mph. Chance of precipitation is 60%.

    High: 77 °F

    T-storms
    Likely

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 7pm. Patchy fog after 5am. Otherwise, mostly cloudy, with a low around 68. Light and variable wind.

    Low: 68 °F

    Chance
    T-storms then
    Patchy Fog

  • Monday

    Monday: Patchy fog before 7am. Otherwise, partly sunny, with a high near 86. Calm wind becoming southeast around 5 mph.

    High: 86 °F

    Patchy Fog
    then Mostly
    Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 72. Southeast wind around 6 mph becoming calm in the evening.

    Low: 72 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 90. Calm wind becoming south around 6 mph in the morning.

    High: 90 °F

    Partly Sunny
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 73.

    Low: 73 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 91.

    High: 91 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 74.

    Low: 74 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92.

    High: 92 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

This Afternoon
Showers and thunderstorms likely, mainly before 5pm. Cloudy, with a steady temperature around 77. Light and variable wind becoming northeast around 5 mph. Chance of precipitation is 60%.
Tonight
A 30 percent chance of showers and thunderstorms, mainly before 7pm. Patchy fog after 5am. Otherwise, mostly cloudy, with a low around 68. Light and variable wind.
Monday
Patchy fog before 7am. Otherwise, partly sunny, with a high near 86. Calm wind becoming southeast around 5 mph.
Monday Night
Mostly cloudy, with a low around 72. Southeast wind around 6 mph becoming calm in the evening.
Tuesday
A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 90. Calm wind becoming south around 6 mph in the morning.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 73.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly sunny, with a high near 91.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 74.
Thursday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92.
Thursday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 73.
Friday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 88.
Friday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 90.
Saturday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 72.
Sunday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 90.
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ABOUT THIS FORECAST

 
Point Forecast:
Alton ILSimilar City Names
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
2:52 pm CDT Jul 13, 2025
Forecast Valid:
3pm CDT Jul 13, 2025-6pm CDT Jul 20, 2025
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation