ZIP code · Walnut · California · United States
ZIP code 91789 — Walnut
ZIP code 91789 serves Walnut, California.
- Postal code
- 91789Single source Value from one source, not cross-checked.
- City
- Walnut
- County
- Los Angeles FIPS 06037
- State
- California
- Country
- United States
- Coordinates
- 34.0183, -117.8546 — precision precise (locality)
View on OpenStreetMap - Population
- 40,933 (ZCTA, ACS 5-year)
- Population density
- 2,579 / sq mi
- Land area
- 15.9 sq mi (41.1 km²) (ZCTA, ACS 5-year)
- Median household income
- $125,742
- Per-capita income
- $49,446
- Median age
- 46.3
- Households
- 12,716
- Housing units
- 13,486
- Median home value
- $936,800
- Median gross rent
- $2,868 / month
- Congressional districts
- CA-38 (also CA-35) (119th Congress)
- USDA hardiness zone
- 10a (30 to 35 °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)
Tools: compare 91789 with another ZIP · ZIPs within 25 miles · distance from 91789
Map of ZIP code 91789
Climate — monthly normals
Warmest month Aug (avg high 92°F), coldest Dec (avg low 42°F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 68 | 67 | 72 | 76 | 78 | 84 | 90 | 92 | 89 | 81 | 74 | 67 |
| Avg low °F | 43 | 45 | 47 | 50 | 54 | 57 | 62 | 63 | 60 | 54 | 47 | 42 |
| Precip in | 2.9 | 4.2 | 2.1 | 1.0 | 0.2 | 0.1 | 0.0 | 0.0 | 0.0 | 1.0 | 0.7 | 2.3 |
NOAA 1991–2020 climate normals from the nearest station: POMONA/FAIRPLEX (6.7 mi) · NOAA NCEI
Places in ZIP 91789
- 11 schools
- 2 colleges & universities
- 4 supermarkets
- 42 restaurants & cafés
- 19 parks
- 16 playgrounds
- 4 gyms & sports centres
- 1 libraries
- 3 post offices
- 4 places of worship
- 2 banks
- 9 gas stations
- 6 EV charging stations
- 4 police & fire stations
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