Severe Thunderstorms and Heavy Rainfall for the Southwest; Heat Spreads Across the Center of the Nation

Moisture will continue to move into areas of the West. This will increase showers and thunderstorms coverage and intensity, with the risk of flash flooding and damaging wind gusts. Meanwhile, heat across the Southwest will expand into the center of the nation this weekend into early next week. Trends favor this heat will spread across the Ohio Valley, mid-Atlantic next week. Read More >

Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

65°F

18°C

Humidity 97%
Wind Speed Calm
Barometer 30.04 in (1016.8 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 30 Aug 1:53 am CDT
Extended Forecast for

Arnold MO

  • Overnight

    Overnight: Mostly clear, with a low around 66. Calm wind becoming south around 5 mph.

    Low: 66 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 97. Heat index values as high as 100. South wind 5 to 7 mph.

    High: 97 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 73. South wind around 6 mph.

    Low: 73 °F

    Mostly Clear

  • Monday

    Monday: Sunny and hot, with a high near 100. Heat index values as high as 104. South wind 5 to 7 mph.

    High: 100 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 75. South wind around 6 mph.

    Low: 75 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 78.

    Low: 78 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 78.

    Low: 78 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 66. Calm wind becoming south around 5 mph.
Sunday
Sunny and hot, with a high near 97. Heat index values as high as 100. South wind 5 to 7 mph.
Sunday Night
Mostly clear, with a low around 73. South wind around 6 mph.
Monday
Sunny and hot, with a high near 100. Heat index values as high as 104. South wind 5 to 7 mph.
Monday Night
Mostly clear, with a low around 75. South wind around 6 mph.
Tuesday
Sunny and hot, with a high near 100.
Tuesday Night
Mostly clear, with a low around 78.
Wednesday
Sunny and hot, with a high near 100.
Wednesday Night
Mostly clear, with a low around 78.
Thursday
Sunny and hot, with a high near 101.
Thursday Night
Mostly clear, with a low around 78.
Friday
Mostly sunny and hot, with a high near 99.
Friday Night
Partly cloudy, with a low around 75.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 96.
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ABOUT THIS FORECAST

 
Point Forecast:
Arnold MO
 38.42°N 90.38°W (Elev. 495 ft)
2:31 am CDT Aug 30, 2026
2am CDT Aug 30, 2026-6pm CDT Sep 5, 2026
 
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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