Residential delivery area · Washington
ZIP Code 99328: Dayton, WA
ZIP code 99328 uses the postal name Dayton, Washington and lies entirely in Columbia County (Census 2020 ZIP-county file). About 3,600 people live there (Census Bureau, ACS 2020-2024). Median household income is $72,756 (Census Bureau, ACS 2020-2024). By Census place, under 1% of its land lies in Dayton; more than 99% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Dayton · its only residential ZIP
- County
- Columbia County
- Census places
- Dayton
- House district
- WA-5 119th Congress
- State
- Washington
- Time zone
- Pacific
- Land area
- 657.3 sq mi · 6 people per sq mi
Where is ZIP code 99328?
99328 centers on 46.276°, -117.871° and covers 657.3 square miles of land plus 3.4 of water. It borders 7 ZIP codes: 99361, 99347, 99359, 99362, 99333, 99143, 97828.
The map draws ZIP code areas only. For the streets inside 99328, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 99328 compare with the rest of Columbia County?
| Measure | 99328 | In Columbia County | In WA |
|---|---|---|---|
| People (ACS 2020-2024) | 3,646 | 1st of 5 | 322nd of 605 |
| Median household income | $73k | 3rd of 4 | 286th of 363 |
| Median home value | $272k | 2nd of 3 | 361st of 392 |
Its median household income is higher than in 51% of U.S. residential ZIP codes, and it is denser than 11% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 99328?
The 2020 Census counted 3,620 people in 99328; the ACS, which samples households over 2020-2024, estimates 3,646. Between the 2010 and 2020 censuses its population fell 3.0% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 3,646
- 2020 Census count
- 3,620−3.0% since 2010 (3,733)
- Households
- 1,667
- Median age
- 49.3
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 99328?
Of the 3,646 people the ACS estimates in 99328, 17.6% are under 18 and 29.6% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (80.4%).
- Under 1817.6%
- 18 to 6452.7%
- 65 and older29.6%
- White, not Hispanic80.4%
- Hispanic or Latino9.1%
- Other or two or more7.8%
- Asian, not Hispanic2.1%
- Black, not Hispanic0.6%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 99328 earn?
Median household income is $72,756 (ACS 2020-2024), the 3rd highest of the 4 ranked ZIP codes in Columbia County. It is not measurably different from 2015-2019 ($67,543 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $72,756
- Income per person
- $40,778
- Below the poverty line
- 9.6%
- Unemployed (of the labor force)
- 4.1%
- Adults 25+ with a bachelor's degree
- 24.0%
- Adjusted gross income per tax return, 2022
- $70,6751,620 returns; wages 58% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 99328?
FHFA's house price index for 99328, built from repeat sales and appraisals of the same homes, rose 97% from 2015 to 2025 and rose 48% from 2020 to 2025, and moved +1.7% in 2025.
- Median home value (owners' estimate)
- $272,100
- Median gross rent
- $982
- Homes owned by their occupants
- 77.4%
- Housing units
- 1,977
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 99328?
100 business establishments had a location in this ZIP code in 2023, 11 fewer than in 2018; the most are in retail trade (ZIP Code Business Patterns).
- Retail trade15
- Wholesale trade11
- Other services (except public administration)11
- Construction8
- Health care and social assistance8
- Accommodation and food services8
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 99328?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 99361 | Waitsburg | 1,992 | $91k | 13.3 mi |
| 99347 | Pomeroy | 2,512 | $65k | 17.4 mi |
| 99359 | Starbuck | 94 | $61k | 21.5 mi |
| 99362 | Walla Walla | 42,853 | $73k | 24.4 mi |
| 99333 | Hooper | 151 | $98k | 31.8 mi |
| 99143 | Lacrosse | 585 | $38k | 33.9 mi |
| 97828 | Enterprise, OR | 3,522 | $59k | 61.9 mi |
| 99329 | Dixie | 127 | – | 16.2 mi (near) |
| 99402 | Asotin | 1,557 | $79k | 25.1 mi (near) |
| 99136 | Hay | 14 | $88k | 27.8 mi (near) |
| 99348 | Prescott | 1,633 | $79k | 28.3 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.