National Weather Service Forecast for: Arnold MO
Issued by: National Weather Service Saint Louis, MO
Updated: 11:46 am CDT May 4, 2026
 
This
Afternoon
This Afternoon: A 30 percent chance of showers and thunderstorms, mainly between 2pm and 3pm. Partly sunny, with a high near 82. Southwest wind 9 to 13 mph, with gusts as high as 24 mph.
Chance
T-storms

 Tonight

Tonight: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4am. Increasing clouds, with a low around 58. Southwest wind 5 to 11 mph, with gusts as high as 23 mph. Chance of precipitation is 60%.
Chance
T-storms then
Showers
Likely
 Tuesday

Tuesday: Showers and possibly a thunderstorm. High near 61. South wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 90%.
Showers

 Tuesday
Night
Tuesday Night: Showers and possibly a thunderstorm. Low around 45. North wind 5 to 9 mph. Chance of precipitation is 90%.
Showers

 Wednesday

Wednesday: A 30 percent chance of showers. Partly sunny, with a high near 60. North wind 5 to 7 mph.
Chance
Showers

 Wednesday
Night
Wednesday Night: A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 43.
Slight Chance
Showers

 Thursday

Thursday: Mostly sunny, with a high near 65.
Mostly Sunny

 Thursday
Night
Thursday Night: Mostly clear, with a low around 46.
Mostly Clear

 Friday

Friday: Mostly sunny, with a high near 73.
Mostly Sunny
Hi 82 °F Lo 58 °F Hi 61 °F Lo 45 °F Hi 60 °F Lo 43 °F Hi 65 °F Lo 46 °F Hi 73 °F

Hazardous Weather Outlook
 

This Afternoon
 
 A 30 percent chance of showers and thunderstorms, mainly between 2pm and 3pm. Partly sunny, with a high near 82. Southwest wind 9 to 13 mph, with gusts as high as 24 mph.
Tonight
 
 A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4am. Increasing clouds, with a low around 58. Southwest wind 5 to 11 mph, with gusts as high as 23 mph. Chance of precipitation is 60%.
Tuesday
 
 Showers and possibly a thunderstorm. High near 61. South wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 90%.
Tuesday Night
 
 Showers and possibly a thunderstorm. Low around 45. North wind 5 to 9 mph. Chance of precipitation is 90%.
Wednesday
 
 A 30 percent chance of showers. Partly sunny, with a high near 60. North wind 5 to 7 mph.
Wednesday Night
 
 A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 43.
Thursday
 
 Mostly sunny, with a high near 65.
Thursday Night
 
 Mostly clear, with a low around 46.
Friday
 
 Mostly sunny, with a high near 73.
Friday Night
 
 A 20 percent chance of showers. Partly cloudy, with a low around 49.
Saturday
 
 Sunny, with a high near 76.
Saturday Night
 
 A 20 percent chance of showers. Partly cloudy, with a low around 52.
Sunday
 
 A 40 percent chance of showers. Mostly sunny, with a high near 75.

 

Forecast from NOAA-NWS for Arnold MO.