National Weather Service Forecast for: Castro Valley CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 7:51 am PDT Jun 4, 2025
 
Today

Today: Sunny, with a high near 79. West wind 5 to 11 mph.
Sunny

 Tonight

Tonight: A slight chance of drizzle after 2am. Mostly clear, with a low around 55. West wind 5 to 9 mph.
Clear then
Slight Chance
Drizzle
 Thursday

Thursday: A slight chance of drizzle before 8am. Sunny, with a high near 78. West wind 5 to 11 mph.
Slight Chance
Drizzle then
Sunny
 Thursday
Night
Thursday Night: Increasing clouds, with a low around 56. West wind 6 to 11 mph.
Increasing
Clouds
 Friday

Friday: Mostly sunny, with a high near 78. West wind 5 to 13 mph.
Mostly Sunny

 Friday
Night
Friday Night: Mostly clear, with a low around 56.
Mostly Clear

 Saturday

Saturday: Sunny, with a high near 79.
Sunny

 Saturday
Night
Saturday Night: Mostly clear, with a low around 56.
Mostly Clear

 Sunday

Sunday: Mostly sunny, with a high near 77.
Mostly Sunny
Hi 79 °F Lo 55 °F Hi 78 °F Lo 56 °F Hi 78 °F Lo 56 °F Hi 79 °F Lo 56 °F Hi 77 °F

 

Today
 
 Sunny, with a high near 79. West wind 5 to 11 mph.
Tonight
 
 A slight chance of drizzle after 2am. Mostly clear, with a low around 55. West wind 5 to 9 mph.
Thursday
 
 A slight chance of drizzle before 8am. Sunny, with a high near 78. West wind 5 to 11 mph.
Thursday Night
 
 Increasing clouds, with a low around 56. West wind 6 to 11 mph.
Friday
 
 Mostly sunny, with a high near 78. West wind 5 to 13 mph.
Friday Night
 
 Mostly clear, with a low around 56.
Saturday
 
 Sunny, with a high near 79.
Saturday Night
 
 Mostly clear, with a low around 56.
Sunday
 
 Mostly sunny, with a high near 77.
Sunday Night
 
 Partly cloudy, with a low around 56.
Monday
 
 Mostly sunny, with a high near 78.
Monday Night
 
 Partly cloudy, with a low around 56.
Tuesday
 
 Mostly sunny, with a high near 77.

 

Forecast from NOAA-NWS for Castro Valley CA.