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.

Drizzle

47°F

8°C

Humidity 94%
Wind Speed W 6 mph
Barometer 29.93 in
Dewpoint 46°F (8°C)
Visibility 10.00 mi
Wind Chill44°F (7°C)
Last update 6 May 2:15 am CDT
Extended Forecast for

Alton ILSimilar City Names

  • Overnight

    Overnight: A 20 percent chance of showers before 4am. Mostly cloudy, with a low around 45. Calm wind.

    Low: 45 °F

    Slight Chance
    Showers

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 60. Calm wind becoming north 5 to 7 mph in the afternoon.

    High: 60 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 42. North wind around 5 mph becoming calm in the evening.

    Low: 42 °F

    Mostly Clear

  • Thursday

    Thursday: Partly sunny, then gradually becoming sunny, with a high near 65. Calm wind becoming west 5 to 9 mph in the morning.

    High: 65 °F

    Becoming
    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 47. South wind 3 to 6 mph.

    Low: 47 °F

    Mostly Clear

  • Friday

    Friday: A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 74. Chance of precipitation is 20%.

    High: 74 °F

    Sunny then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am. Partly cloudy, with a low around 51. Chance of precipitation is 50%.

    Low: 51 °F

    Chance
    Showers

  • Saturday

    Saturday: Sunny, with a high near 80.

    High: 80 °F

    Sunny

  • Saturday Night

    Saturday Night: A 50 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 57.

    Low: 57 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

Detailed Forecast

Overnight
A 20 percent chance of showers before 4am. Mostly cloudy, with a low around 45. Calm wind.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 60. Calm wind becoming north 5 to 7 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 42. North wind around 5 mph becoming calm in the evening.
Thursday
Partly sunny, then gradually becoming sunny, with a high near 65. Calm wind becoming west 5 to 9 mph in the morning.
Thursday Night
Mostly clear, with a low around 47. South wind 3 to 6 mph.
Friday
A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 74. Chance of precipitation is 20%.
Friday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am. Partly cloudy, with a low around 51. Chance of precipitation is 50%.
Saturday
Sunny, with a high near 80.
Saturday Night
A 50 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 57.
Sunday
A 30 percent chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 70.
Sunday Night
Partly cloudy, with a low around 47.
Monday
Sunny, with a high near 71.
Monday Night
A slight chance of freezing rain. Mostly clear, with a low around 50. Chance of precipitation is 20%.
Tuesday
Mostly sunny, with a high near 77.
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ABOUT THIS FORECAST

 
Point Forecast:
Alton ILSimilar City Names
 38.91°N 90.16°W (Elev. 505 ft)
Last Update:
1:26 am CDT May 6, 2026
Forecast Valid:
2am CDT May 6, 2026-6pm CDT May 12, 2026
 
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