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

Hazardous Weather Conditions

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

68°F

20°C

Humidity 76%
Wind Speed SW 3 mph
Barometer 30.00 in (1015.6 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Last update 20 Jun 3:53 am CDT
Extended Forecast for

Arnold MO

Flood Watch June 21, 07:00am until June 22, 07:00am
Click here for hazard details and duration
Flood Watch

  • Today

    Today: Mostly sunny, with a high near 85. Light and variable wind.

    High: 85 °F

    Mostly Sunny

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 68. Light and variable wind.

    Low: 68 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Sunday

    Sunday: Showers and thunderstorms, mainly before 1pm. High near 85. South wind 5 to 11 mph, with gusts as high as 25 mph. Chance of precipitation is 80%.

    High: 85 °F

    T-storms

  • Sunday Night

    Sunday Night: Showers and thunderstorms, mainly before 1am. Low around 65. Southwest wind 7 to 9 mph becoming northwest after midnight. Chance of precipitation is 90%.

    Low: 65 °F

    T-storms

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 79. North wind around 7 mph.

    High: 79 °F

    Slight Chance
    T-storms

  • Monday Night

    Monday Night: Partly cloudy, with a low around 61.

    Low: 61 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 63.

    Low: 63 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 85. Light and variable wind.
Tonight
A 20 percent chance of showers and thunderstorms after 4am. Mostly cloudy, with a low around 68. Light and variable wind.
Sunday
Showers and thunderstorms, mainly before 1pm. High near 85. South wind 5 to 11 mph, with gusts as high as 25 mph. Chance of precipitation is 80%.
Sunday Night
Showers and thunderstorms, mainly before 1am. Low around 65. Southwest wind 7 to 9 mph becoming northwest after midnight. Chance of precipitation is 90%.
Monday
A 20 percent chance of showers and thunderstorms before 1pm. Partly sunny, with a high near 79. North wind around 7 mph.
Monday Night
Partly cloudy, with a low around 61.
Tuesday
Mostly sunny, with a high near 81.
Tuesday Night
Mostly clear, with a low around 63.
Wednesday
Mostly sunny, with a high near 84.
Wednesday Night
Partly cloudy, with a low around 63.
Thursday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 83.
Thursday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 63.
Friday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 83.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.42°N 90.38°W (Elev. 495 ft)
Last Update:
2:56 am CDT Jun 20, 2026
Forecast Valid:
4am CDT Jun 20, 2026-6pm CDT Jun 26, 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