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

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Partly Cloudy

81°F

27°C

Humidity 69%
Wind Speed W 8 mph
Barometer 29.91 in (1012.5 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 15 Oct 4:53 pm CDT
Extended Forecast for

Arnold MO

  • This Afternoon

    This Afternoon: A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 81. Southwest wind around 8 mph.

    High: 81 °F

    Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms likely before 2am, then a slight chance of showers between 2am and 4am. Increasing clouds, with a low around 46. Northwest wind 8 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 70%.

    Low: 46 °F

    Showers
    Likely then
    Chance
    Showers

  • Friday

    Friday: A 20 percent chance of showers after 4pm. Partly sunny, with a high near 57. Northwest wind 14 to 16 mph, with gusts as high as 26 mph.

    High: 57 °F

    Partly Sunny
    then Slight
    Chance
    Showers

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 39. Northwest wind 7 to 14 mph, with gusts as high as 23 mph.

    Low: 39 °F

    Mostly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 60. North wind around 5 mph becoming calm in the afternoon.

    High: 60 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 36.

    Low: 36 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 39.

    Low: 39 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 72.

    High: 72 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 81. Southwest wind around 8 mph.
Tonight
Showers and thunderstorms likely before 2am, then a slight chance of showers between 2am and 4am. Increasing clouds, with a low around 46. Northwest wind 8 to 14 mph, with gusts as high as 23 mph. Chance of precipitation is 70%.
Friday
A 20 percent chance of showers after 4pm. Partly sunny, with a high near 57. Northwest wind 14 to 16 mph, with gusts as high as 26 mph.
Friday Night
Mostly cloudy, with a low around 39. Northwest wind 7 to 14 mph, with gusts as high as 23 mph.
Saturday
Sunny, with a high near 60. North wind around 5 mph becoming calm in the afternoon.
Saturday Night
Clear, with a low around 36.
Sunday
Sunny, with a high near 67.
Sunday Night
Mostly clear, with a low around 39.
Monday
Mostly sunny, with a high near 72.
Monday Night
Partly cloudy, with a low around 43.
Tuesday
Mostly sunny, with a high near 76.
Tuesday Night
Mostly clear, with a low around 47.
Wednesday
Sunny, with a high near 79.
Wednesday Night
Mostly clear, with a low around 49.
Thursday
Sunny, with a high near 82.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.42°N 90.38°W (Elev. 495 ft)
Last Update:
2:26 pm CDT Oct 15, 2026
Forecast Valid:
5pm CDT Oct 15, 2026-6pm CDT Oct 22, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation