National Weather Service Forecast for: Arnold MO
Issued by: National Weather Service Saint Louis, MO
Updated: 10:06 pm CST Feb 1, 2026
 
Overnight

Overnight: Mostly cloudy, with a low around 23. Southwest wind around 5 mph becoming calm.
Mostly Cloudy
 Monday

Monday: Partly sunny, with a high near 39. Light and variable wind.
Partly Sunny
 Monday
Night
Monday Night: Mostly cloudy, with a low around 29. Light east wind.
Mostly Cloudy
 Tuesday

Tuesday: A 20 percent chance of snow. Mostly cloudy, with a high near 35. North wind 3 to 7 mph.
Slight Chance
Snow
 Tuesday
Night
Tuesday Night: Mostly cloudy, with a low around 19. Light north wind.
Mostly Cloudy
 Wednesday

Wednesday: Mostly sunny, with a high near 31.
Mostly Sunny
 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 15.
Mostly Clear
 Thursday

Thursday: Mostly sunny, with a high near 43.
Mostly Sunny
 Thursday
Night
Thursday Night: Mostly clear, with a low around 32.
Mostly Clear
Lo 23 °F Hi 39 °F Lo 29 °F Hi 35 °F Lo 19 °F Hi 31 °F Lo 15 °F Hi 43 °F Lo 32 °F

Hazardous Weather Outlook
 

Overnight
 
 Mostly cloudy, with a low around 23. Southwest wind around 5 mph becoming calm.
Monday
 
 Partly sunny, with a high near 39. Light and variable wind.
Monday Night
 
 Mostly cloudy, with a low around 29. Light east wind.
Tuesday
 
 A 20 percent chance of snow. Mostly cloudy, with a high near 35. North wind 3 to 7 mph.
Tuesday Night
 
 Mostly cloudy, with a low around 19. Light north wind.
Wednesday
 
 Mostly sunny, with a high near 31.
Wednesday Night
 
 Mostly clear, with a low around 15.
Thursday
 
 Mostly sunny, with a high near 43.
Thursday Night
 
 Mostly clear, with a low around 32.
Friday
 
 Mostly sunny, with a high near 48.
Friday Night
 
 Partly cloudy, with a low around 22.
Saturday
 
 Sunny, with a high near 39.
Saturday Night
 
 Partly cloudy, with a low around 25.
Sunday
 
 Mostly sunny, with a high near 45.

 

Forecast from NOAA-NWS for Arnold MO.