Below is a list of Castro Valley CA zip codes. For your research we have also included Castro Valley Area Code, Time Zone, UTC and the local Alameda County FIPS Code. Each Castro Valley California zip code has a center Longitude / Latitude point (the Castro Valley center is -122.07399749756 / 37.710899353027). For your convenience we have also indicated if that zip code in Castro Valley observes Daylight Savings time.