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

87°F

31°C

Humidity 75%
Wind Speed Calm
Barometer 29.86 in (1010.5 mb)
Dewpoint 78°F (26°C)
Visibility 10.00 mi
Heat Index100°F (38°C)
Last update 26 Jul 8:53 pm CDT
Extended Forecast for

Arnold MO

Extreme Heat Warning July 26, 09:41pm until July 27, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning July 26, 09:41pm until July 27, 09:00pm

    NOW until 9:00pm Mon

    Extreme Heat Warning

  • Tonight

    Low: 78 °F

    Partly Cloudy

  • Monday

    Monday: Sunny and hot, with a high near 99. Heat index values as high as 112. Calm wind becoming southwest 5 to 7 mph in the morning.

    High: 99 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 80. Southwest wind 3 to 5 mph.

    Low: 80 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 94. Heat index values as high as 105. Northwest wind 5 to 7 mph becoming north in the afternoon.

    High: 94 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 72. North wind 5 to 7 mph becoming calm in the evening.

    Low: 72 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 90.

    High: 90 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 69.

    Low: 69 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 91.

    High: 91 °F

    Sunny

Detailed Forecast

Tonight
Partly cloudy, with a low around 78. Calm wind.
Monday
Sunny and hot, with a high near 99. Heat index values as high as 112. Calm wind becoming southwest 5 to 7 mph in the morning.
Monday Night
Mostly clear, with a low around 80. Southwest wind 3 to 5 mph.
Tuesday
Mostly sunny, with a high near 94. Heat index values as high as 105. Northwest wind 5 to 7 mph becoming north in the afternoon.
Tuesday Night
Partly cloudy, with a low around 72. North wind 5 to 7 mph becoming calm in the evening.
Wednesday
Sunny, with a high near 90.
Wednesday Night
Mostly clear, with a low around 69.
Thursday
Sunny, with a high near 91.
Thursday Night
A 30 percent chance of showers after 1am. Partly cloudy, with a low around 71.
Friday
A chance of showers, with thunderstorms also possible after 1pm. Partly sunny, with a high near 86. Chance of precipitation is 50%.
Friday Night
A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 69.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 85.
Saturday Night
Mostly clear, with a low around 68.
Sunday
Sunny, with a high near 86.
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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:
8:41 pm CDT Jul 26, 2026
Forecast Valid:
9pm CDT Jul 26, 2026-6pm CDT Aug 2, 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