Zip Code 91789
Walnut, California — Los Angeles County
📍 ZIP code 91789 is in Walnut, Los Angeles County, California.
ZIP code 91789 is located in Walnut, Los Angeles County, California. It is a zip code in the Pacific (PST/PDT) Time Zone with an estimated population of 40,933. The area code for ZIP code 91789 is 805.
Quick Answer
Zip code 91789 is in Walnut, California (Los Angeles County). It has a population of 40,933, median household income of $125,742, and median home value of $936,800.
Population
40,933
Income
$125,742
Home Value
$936,800
Climate
90°F / 43°F
About Zip Code 91789
Zip code 91789 is located in Walnut, California, within Los Angeles County. Home to approximately 40,933 residents, this area sits at an elevation of 628 ft and falls within the Pacific (PST/PDT) timezone. The local area code is 805.
The median household income is $125,742 per year, which is above the national median of $70,784. Homes in this zip code have a median value of $936,800, and the cost of living index is 250 (150% above the national average of 100).
Summers average a high of 90°F while winters drop to 43°F. The area receives about 14 in of rain annually. The zip code covers 15.6 square miles of land area.
Key Statistics
40,933
$125,742
$936,800
Pacific (PST/PDT)
805
628 ft
15.6 sq mi
46.3
13,486
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Compare With Nearby Zip Codes
| Metric | 91789 | 91792 | 91765 | 91791 | 91748 | 91724 |
|---|---|---|---|---|---|---|
| City | Walnut, CA | West Covina, CA | Diamond Bar, CA | West Covina, CA | Rowland Heights, CA | Covina, CA |
| Population | 40,933 | 30,921 | 44,779 | 33,321 | 43,137 | 28,113 |
| Median Income | $125,742 | $96,383 | $104,737 | $100,365 | $83,455 | $102,129 |
| Home Value | $936,800 | $653,800 | $878,900 | $782,500 | $781,500 | $722,600 |
| Cost of Living | 250 | 183 | 236 | 205 | 201 | 194 |
| Median Age | 46.3 | 40.5 | 45.7 | 44 | 44.7 | 39.1 |
Cost of Living
100 = National Average. Walnut's cost of living is 150% above the national average.
vs. State Avg
Above
Affordability
Expensive
Income-to-Home
7.5x
Demographics
Zip code 91789 has a population of 40,933 people with a median age of 46.3. There are 13,486 housing units in this area.
Racial & Ethnic Composition
Source: U.S. Census Bureau American Community Survey estimates.
Population History
Walnut (91789) population trend from 2010 to 2024
↑ 645.3%Source: U.S. Census Bureau estimates and American Community Survey data.
Climate & Weather
90°F
43°F
14 in
0 in
Walnut experiences hot summers with average highs around 90°F. Winters are mild with lows averaging 43°F. The area receives virtually no snowfall.
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Housing & Economy
Median Home Value
$936,800
Median Household Income
$125,742
With 13,486 housing units across 15.6 square miles, 91789 has a housing density of 864 units per square mile. The home price-to-income ratio is 7.5x.
Location & Geography
Latitude
34.0182°
Longitude
-117.8548°
Land Area
15.6 sq mi
Water Area
0 sq mi
Nearby Zip Codes
Zip codes closest to 91789 (Walnut, CA) with distances:
ZIP Codes with Similar Income Nationwide
The five U.S. ZIP codes whose median household income is closest to 91789's $125,742. A way to compare Walnut to economically similar communities elsewhere in the country.
Computed from U.S. Census Bureau ACS 5-Year Estimates by the Zip Code Near Me Data Team.
ZIP Codes with Similar Demographics
The five U.S. ZIP codes whose racial and ethnic composition most closely matches 91789 (Walnut, CA). Similarity is measured by cosine distance on the five-category ACS demographic vector.
Computed from U.S. Census Bureau ACS 5-Year Estimates by the Zip Code Near Me Data Team.
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People Also Ask
What zip code is Walnut, California?
Walnut, California uses zip code 91789.
What county is zip code 91789 in?
Zip code 91789 is located in Los Angeles County, California.
What is the population of zip code 91789?
The population of zip code 91789 is 40,933 with a median age of 46.3.
Is 91789 in Walnut, California?
Yes, zip code 91789 is in Walnut, Los Angeles County, California. The area code is 805.
Frequently Asked Questions
What city is zip code 91789 in?
Zip code 91789 is in Walnut, California. It is part of Los Angeles County and uses the Pacific (PST/PDT) timezone.
What is zip code 91789?
Zip code 91789 is a U.S. postal code in Walnut, California (Los Angeles County). It has a population of 40,933 and covers 15.6 square miles.
What is the population of zip code 91789?
The population of zip code 91789 (Walnut, CA) is 40,933 with a median age of 46.3. There are approximately 13,486 housing units in this area.
What is the median income in zip code 91789?
The median household income in zip code 91789 (Walnut, CA) is $125,742 per year. The cost of living index is 250 (100 = national average).
What is the average home price in zip code 91789?
The median home value in zip code 91789 (Walnut, CA) is $936,800. The cost of living index is 250 compared to the national average of 100.
What county is zip code 91789 in?
Zip code 91789 is located in Los Angeles County, California. The primary city is Walnut.
What is the area code for zip code 91789?
Zip code 91789 in Walnut, CA uses area code 805. It is located in the Pacific (PST/PDT) timezone.
Is zip code 91789 a good place to live?
Zip code 91789 (Walnut, CA) has a cost of living index of 250 (100 = national average), a median household income of $125,742, and median home values of $936,800. The median age is 46.3. Visit the full page for demographics, climate, and nearby zip code comparisons.
What is the cost of living in zip code 91789?
The cost of living index for zip code 91789 (Walnut, CA) is 250, where 100 represents the national average. This area is above the national average. Median home value: $936,800.
What schools serve zip code 91789?
Zip code 91789 in Walnut, California is served by the local school district of Los Angeles County. For specific school information, check your state's department of education or GreatSchools.org.
All demographic data on this page is sourced from the U.S. Census Bureau American Community Survey (ACS) 5-Year Estimates. ZIP code boundary and delivery data is sourced from the United States Postal Service (USPS). Data is updated periodically and may not reflect the most current figures. Census Bureau ZIP Code Tabulation Areas (ZCTAs) may differ slightly from USPS ZIP code boundaries.
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Data Sources
- Population, income, housing, age, and demographics
- U.S. Census Bureau, American Community Survey 5-Year Estimates, 2019-2023 vintage.
- ZIP to city and county mapping
- USPS and HUD-USPS ZIP-County Crosswalk.
- Time zones and area codes
- IANA tz database and NANPA.
- Elevation
- U.S. Geological Survey National Elevation Dataset (NED), via the USGS Elevation Point Query Service. Mapped to each ZCTA centroid coordinates. Last refreshed 2026-05-19.
- Last refreshed
- 2026-05-18.