91788 ZIP Code — Walnut, CA
Los Angeles County, California
ZIP code 91788 is located in Walnut, California, within Los Angeles County. It covers approximately 0.00 square miles and serves a population of 0 residents. This is a standard ZIP code in the Pacific (PT) timezone, served by area code 909.
0
population
0.00
sq mi land
Standard
ZIP type
Pacific (PT)
timezone
91788 ZIP code map
Cities in ZIP code 91788
Below are the cities the US Postal Service accepts for ZIP code 91788. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Walnut | Acceptable |
Demographics
updated 06/2026
| Population | |
|---|---|
| Total population | 0 |
| Population density | 0 / sq mi |
| State FIPS | 06 |
| County FIPS | 037 |
| Geography | |
|---|---|
| Land area | 0.00 sq mi |
| Water area | 0.00 sq mi |
| Latitude | 34.0203 |
| Longitude | -117.8647 |
| Timezone | Pacific (PT) |
| Area code | 909 |