ZIP Code 94552 – Castro Valley, CA
Castro Valley, California · Alameda County · Pacific time
| ZIP code | 94552 |
|---|---|
| City | Castro Valley |
| State | California |
| County | Alameda County |
| Population | 14,506 |
| Time zone | Pacific · local time |
| ZIP type | Standard (has a Census ZCTA area) |
| Land area | 51.8 sq mi |
| Center (lat, long) | 37.7058, -122.0076 |
Area codes in this area
These are the area codes that most often serve ZIP 94552 (including overlays). The exact area code depends on the phone number — landlines, mobiles and overlays can differ even on the same street.
Map
Nearby ZIP codes
About ZIP 94552
ZIP code 94552 is assigned to Castro Valley, California. It lies in Alameda County. Its Census area covers about 51.8 square miles of land. The closest neighboring ZIP is 94542 (Hayward), about 3.6 miles away.
Every address in 94552 also has a 4-digit add-on code (ZIP+4) that points to a smaller delivery area. Use the box above to find it.
Sources: US Census Bureau (ZCTA, county relationship files), GeoNames (CC BY 4.0), NANPA via NumberResearch.org (CC BY 4.0). Map © OpenStreetMap contributors. ZIP areas are approximate. Population: U.S. Census Bureau, ACS 5-year estimates, 2024 (ZCTA). Data sources