ZIP code · Castro Valley · California · United States

ZIP code 94546 — Castro Valley

ZIP code 94546 serves Castro Valley, California.

Postal code
94546
Single source Value from one source, not cross-checked.
City
Castro Valley
County
Alameda FIPS 06001
State
California
Country
United States
Coordinates
37.7015, -122.0782 — precision precise (locality)
View on OpenStreetMap
Population
45,848 (ZCTA, ACS 5-year)
Population density
2,873 / sq mi
Land area
16 sq mi (41.3 km²) (ZCTA, ACS 5-year)
Median household income
$125,780
Per-capita income
$55,870
Median age
42.1
Households
15,918
Housing units
16,398
Median home value
$976,300
Median gross rent
$2,506 / month
Congressional district
CA-14 (119th Congress)
USDA hardiness zone
9b (25 to 30 °F)
Planting / growing zone from the 2023 USDA Plant Hardiness Zone Map: average annual extreme minimum temperature, 1991–2020.
Time zone
America/Los_Angeles (UTC−8 / UTC−7 DST)
Area code
831
Telephone area codes serving this ZIP (NANPA central-office assignments). A ZIP and an area code are different boundaries; at a border both codes may apply.

Climate — monthly normals

Warmest month Sep (avg high 77°F), coldest Dec (avg low 43°F).

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high °F596264676974757677746559
Avg low °F434547505255575858544743
Precip in2.93.12.41.20.60.10.00.10.10.81.53.2

NOAA 1991–2020 climate normals from the nearest station: HAYWARD AIR TERMINAL (3.9 mi) · NOAA NCEI

Places in ZIP 94546

Places mapped inside this ZIP’s ZCTA area in OpenStreetMap. OSM is community-maintained: counts reflect what has been mapped, and completeness varies by area — treat them as at-least figures. © OpenStreetMap contributors (ODbL) · Methodology

About this page

US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.

GeoNames · U.S. Census Bureau (ACS) · U.S. Census Bureau · NOAA NCEI · usda-phzm. Data generated on 2026-08-21. Methodology · Report an error on this page