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.

Fair

36°F

2°C

Humidity 67%
Wind Speed Calm
Barometer 30.11 in (1020.0 mb)
Dewpoint 26°F (-3°C)
Visibility 10.00 mi
Last update 12 Jan 9:53 pm CST
Extended Forecast for

Arnold MO

  • Tonight

    Tonight: Mostly clear, with a low around 41. Southwest wind 3 to 6 mph.

    Low: 41 °F

    Mostly Clear

  • Tuesday

    Tuesday: Increasing clouds, with a high near 63. West wind 7 to 11 mph, with gusts as high as 29 mph.

    High: 63 °F

    Increasing
    Clouds

  • Tuesday Night

    Tuesday Night: A 30 percent chance of rain, mainly between 7pm and 11pm. Mostly cloudy, with a low around 37. West wind 7 to 13 mph, with gusts as high as 22 mph.

    Low: 37 °F

    Chance Rain

  • Wednesday

    Wednesday: Partly sunny, with a temperature rising to near 43 by 11am, then falling to around 34 during the remainder of the day. Northwest wind 10 to 16 mph, with gusts as high as 31 mph.

    High: 43 °F⇓

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 17. North wind 6 to 13 mph, with gusts as high as 24 mph.

    Low: 17 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 33.

    High: 33 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 25.

    Low: 25 °F

    Mostly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 44.

    High: 44 °F

    Partly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 20.

    Low: 20 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 41. Southwest wind 3 to 6 mph.
Tuesday
Increasing clouds, with a high near 63. West wind 7 to 11 mph, with gusts as high as 29 mph.
Tuesday Night
A 30 percent chance of rain, mainly between 7pm and 11pm. Mostly cloudy, with a low around 37. West wind 7 to 13 mph, with gusts as high as 22 mph.
Wednesday
Partly sunny, with a temperature rising to near 43 by 11am, then falling to around 34 during the remainder of the day. Northwest wind 10 to 16 mph, with gusts as high as 31 mph.
Wednesday Night
Mostly clear, with a low around 17. North wind 6 to 13 mph, with gusts as high as 24 mph.
Thursday
Mostly sunny, with a high near 33.
Thursday Night
Mostly cloudy, with a low around 25.
Friday
Partly sunny, with a high near 44.
Friday Night
Mostly cloudy, with a low around 20.
Saturday
Partly sunny, with a high near 31.
Saturday Night
Partly cloudy, with a low around 10.
Sunday
Mostly sunny, with a high near 29.
Sunday Night
Mostly clear, with a low around 14.
M.L.King Day
Mostly sunny, with a high near 37.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.45°N 90.38°W (Elev. 499 ft)
Last Update:
9:41 pm CST Jan 12, 2026
Forecast Valid:
10pm CST Jan 12, 2026-6pm CST Jan 19, 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