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

38°F

3°C

Humidity 97%
Wind Speed Calm
Barometer 30.05 in (1017.5 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Last update 10 Jan 3:53 am CST
Extended Forecast for

Arnold MO

  • Overnight

    Overnight: A 20 percent chance of rain. Mostly cloudy, with a low around 39. Light northwest wind.

    Low: 39 °F

    Slight Chance
    Rain

  • Saturday

    Saturday: A 30 percent chance of rain, mainly before 9am. Cloudy through mid morning, then gradual clearing, with a high near 48. Northwest wind 5 to 14 mph, with gusts as high as 24 mph.

    High: 48 °F

    Chance Rain
    then Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy during the early evening, then gradual clearing, with a low around 26. Northwest wind 7 to 11 mph, with gusts as high as 25 mph.

    Low: 26 °F

    Gradual
    Clearing

  • Sunday

    Sunday: Sunny, with a high near 40. Northwest wind 5 to 10 mph becoming light west in the afternoon. Winds could gust as high as 23 mph.

    High: 40 °F

    Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 25. Calm wind becoming southwest around 6 mph after midnight.

    Low: 25 °F

    Clear

  • Monday

    Monday: Sunny, with a high near 53.

    High: 53 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

  • Tuesday

    Tuesday: Partly sunny, with a high near 61.

    High: 61 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 38.

    Low: 38 °F

    Mostly Cloudy

Detailed Forecast

Overnight
A 20 percent chance of rain. Mostly cloudy, with a low around 39. Light northwest wind.
Saturday
A 30 percent chance of rain, mainly before 9am. Cloudy through mid morning, then gradual clearing, with a high near 48. Northwest wind 5 to 14 mph, with gusts as high as 24 mph.
Saturday Night
Mostly cloudy during the early evening, then gradual clearing, with a low around 26. Northwest wind 7 to 11 mph, with gusts as high as 25 mph.
Sunday
Sunny, with a high near 40. Northwest wind 5 to 10 mph becoming light west in the afternoon. Winds could gust as high as 23 mph.
Sunday Night
Clear, with a low around 25. Calm wind becoming southwest around 6 mph after midnight.
Monday
Sunny, with a high near 53.
Monday Night
Mostly clear, with a low around 37.
Tuesday
Partly sunny, with a high near 61.
Tuesday Night
Mostly cloudy, with a low around 38.
Wednesday
Mostly cloudy, with a high near 46.
Wednesday Night
Mostly cloudy, with a low around 21.
Thursday
Mostly sunny, with a high near 39.
Thursday Night
Mostly cloudy, with a low around 27.
Friday
Partly sunny, with a high near 46.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.4°N 90.38°W (Elev. 495 ft)
Last Update:
4:36 am CST Jan 10, 2026
Forecast Valid:
5am CST Jan 10, 2026-6pm CST Jan 16, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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