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.

Light Rain Fog/Mist

75°F

24°C

Humidity 94%
Wind Speed S 6 mph
Barometer 29.95 in (1013.9 mb)
Dewpoint 73°F (23°C)
Visibility 5.00 mi
Last update 15 Oct 12:53 pm CDT
Extended Forecast for

Arnold MO

  • This Afternoon

    This Afternoon: Showers and possibly a thunderstorm. High near 81. Southwest wind 7 to 9 mph. Chance of precipitation is 90%.

    High: 81 °F

    Showers

  • 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
Showers and possibly a thunderstorm. High near 81. Southwest wind 7 to 9 mph. Chance of precipitation is 90%.
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 42.
Tuesday
Sunny, with a high near 74.
Tuesday Night
Mostly clear, with a low around 45.
Wednesday
Sunny, with a high near 78.
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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:
11:21 am CDT Oct 15, 2026
Forecast Valid:
1pm CDT Oct 15, 2026-6pm CDT Oct 21, 2026
 
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