National Weather Service Forecast for: Arnold MO
Issued by: National Weather Service Saint Louis, MO
Updated: 10:46 am CDT Oct 6, 2026
 
This
Afternoon
This Afternoon: Sunny, with a high near 80. South wind 3 to 5 mph.
Sunny
 Tonight

Tonight: Mostly clear, with a low around 55. Light and variable wind.
Mostly Clear
 Wednesday

Wednesday: Sunny, with a high near 88. Southwest wind 5 to 7 mph becoming west in the afternoon.
Sunny
 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 58. Light northwest wind.
Mostly Clear
 Thursday

Thursday: Sunny, with a high near 84. Light north wind.
Sunny
 Thursday
Night
Thursday Night: Mostly clear, with a low around 54.
Mostly Clear
 Friday

Friday: Sunny, with a high near 86.
Sunny
 Friday
Night
Friday Night: Clear, with a low around 58.
Clear
 Saturday

Saturday: Sunny, with a high near 89.
Sunny
Hi 80 °F Lo 55 °F Hi 88 °F Lo 58 °F Hi 84 °F Lo 54 °F Hi 86 °F Lo 58 °F Hi 89 °F

 

This Afternoon
 
 Sunny, with a high near 80. South wind 3 to 5 mph.
Tonight
 
 Mostly clear, with a low around 55. Light and variable wind.
Wednesday
 
 Sunny, with a high near 88. Southwest wind 5 to 7 mph becoming west in the afternoon.
Wednesday Night
 
 Mostly clear, with a low around 58. Light northwest wind.
Thursday
 
 Sunny, with a high near 84. Light north wind.
Thursday Night
 
 Mostly clear, with a low around 54.
Friday
 
 Sunny, with a high near 86.
Friday Night
 
 Clear, with a low around 58.
Saturday
 
 Sunny, with a high near 89.
Saturday Night
 
 A 30 percent chance of showers after 1am. Partly cloudy, with a low around 61.
Sunday
 
 A 30 percent chance of showers. Mostly sunny, with a high near 82.
Sunday Night
 
 Partly cloudy, with a low around 60.
Columbus Day
 
 Mostly sunny, with a high near 87.

 

Forecast from NOAA-NWS for Arnold MO.