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

80°F

27°C

Humidity 74%
Wind Speed S 7 mph
Barometer 30.03 in (1016.3 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 9 Aug 10:53 pm CDT
Extended Forecast for

Arnold MO

  • Tonight

    Tonight: Partly cloudy, with a low around 74. South wind 5 to 7 mph.

    Low: 74 °F

    Partly Cloudy

  • Sunday

    Sunday: A slight chance of showers between 9am and 1pm, then a slight chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 94. Heat index values as high as 101. South wind 5 to 10 mph. Chance of precipitation is 20%.

    High: 94 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 73. South wind 3 to 8 mph.

    Low: 73 °F

    Partly Cloudy

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 93. Heat index values as high as 101. Calm wind becoming south around 6 mph in the afternoon.

    High: 93 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Monday Night

    Monday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 73. South wind around 5 mph becoming calm in the evening.

    Low: 73 °F

    Slight Chance
    T-storms

  • Tuesday

    Tuesday: A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Chance of precipitation is 40%.

    High: 92 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.

    Low: 72 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 91. Chance of precipitation is 30%.

    High: 91 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.

    Low: 72 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
Partly cloudy, with a low around 74. South wind 5 to 7 mph.
Sunday
A slight chance of showers between 9am and 1pm, then a slight chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 94. Heat index values as high as 101. South wind 5 to 10 mph. Chance of precipitation is 20%.
Sunday Night
Partly cloudy, with a low around 73. South wind 3 to 8 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 93. Heat index values as high as 101. Calm wind becoming south around 6 mph in the afternoon.
Monday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 73. South wind around 5 mph becoming calm in the evening.
Tuesday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Chance of precipitation is 40%.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.
Wednesday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 91. Chance of precipitation is 30%.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 72.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 91. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 72.
Friday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93.
Friday Night
Partly cloudy, with a low around 73.
Saturday
Mostly sunny, with a high near 95.
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ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.42°N 90.35°W (Elev. 400 ft)
Last Update:
10:46 pm CDT Aug 9, 2025
Forecast Valid:
11pm CDT Aug 9, 2025-6pm CDT Aug 16, 2025
 
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