99328 ZIP Code, Dayton, WA
99328 is a ZIP code in Dayton, Washington in Columbia County. It covers 657 square miles of land. The closest ZIP codes are 99361, 99329 and 99347. 3,646 people live here in 1,667 households. It is rural, with fewer than 100 people per square mile, and most homes are owner-occupied (77%). Median household income is $72,756, below the Washington median of $98,141; the median age is 49.3, older than most ZIP codes.
Quick facts
- Mailing city: Dayton, WA
- County: Columbia County
- Land area: 657 sq mi
- Population: 3,646
- Median household income: $72,756
- Carrier routes: 5 (1,640 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 3,646 |
| Households | 1,667 |
| Median household income | $72,756 |
| Income per person | $40,778 |
| Median age | 49.3 |
| Homeowners | 77.4% |
| Median home value | $272,100 |
| Median rent | $982 |
| Bachelor's degree or higher | 24.0% |
| Average commute (minutes) | 21.4 |
| Households with kids under 18 | 19.4% |
| Moved in the past year | 13.2% |
| Below the poverty line | 9.6% |
| Broadband internet | 81.1% |
| Speak a non-English language at home | 8.5% |
Household income
| % of households | Value |
|---|---|
| <$10K | 5.8% |
| $10–15K | 4.6% |
| $15–25K | 6.8% |
| $25–35K | 4.3% |
| $35–50K | 10.6% |
| $50–75K | 20.3% |
| $75–100K | 11.2% |
| $100–150K | 26.3% |
| $150–200K | 5.3% |
| $200K+ | 4.9% |
Age
| % of all residents | Value |
|---|---|
| <10 | 8.9% |
| 10–19 | 9.0% |
| 20–24 | 5.7% |
| 25–34 | 9.2% |
| 35–44 | 13.6% |
| 45–54 | 9.4% |
| 55–64 | 14.5% |
| 65–74 | 17.6% |
| 75+ | 12.1% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 34.3% |
| Owned outright | 31.1% |
| Rented | 19.0% |
| Vacant | 15.6% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 81.6% |
| Townhome | 1.5% |
| 2–4 units | 2.3% |
| 5–19 units | 2.7% |
| 20+ units | 0.6% |
| Mobile / other | 11.4% |
Businesses in 99328
100 business establishments with 876 employees (ZIP Codes Business Patterns 2023).
- Retail Trade: 15
- Wholesale Trade: 11
- Other Services (except Public Administration): 11
- Construction: 8
- Health Care and Social Assistance: 8
- Accommodation and Food Services: 8
- Manufacturing: 6
- Professional, Scientific, and Technical Services: 6
EDDM carrier routes
99328 has 5 USPS carrier routes with 1,640 residential and 160 business mailboxes. Open the EDDM route map.
Carrier routes in 99328
99328 has 5 USPS carrier routes (2 city (C), 3 rural (R)) with 1,640 residential and 160 business mailboxes. Routes range from 34 homes (R001) to 644 homes (C002); the median route has 256 homes. The Census counted 1,667 households in 99328 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 2 |
| 250–499 | 2 |
| 500–749 | 1 |
| 750–999 | 0 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 99328 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route C001 — USPS business mailboxes 72, 461 homes
- Route C002 — USPS business mailboxes 54, 644 homes
- Route R002 — USPS business mailboxes 28, 245 homes
- Route R003 — USPS business mailboxes 5, 256 homes
- Route R001 — USPS business mailboxes 1, 34 homes
Select these 5 routes on the route map
Every carrier route in 99328
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| C001 | City | 461 | 72 | $75,572 | — | — | — |
| C002 | City | 644 | 54 | $68,495 | — | — | — |
| R001 | Rural | 34 | 1 | $75,572 | — | — | — |
| R002 | Rural | 245 | 28 | $75,572 | — | — | — |
| R003 | Rural | 256 | 5 | $84,672 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 99328 on the EDDM route map.
How route demographics are estimated
Mailbox counts come from USPS; demographics are estimates
The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).
How a route gets its figures: the block-group length-share method
We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.
Margins of error
Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.
Different years
USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.
Why some routes show identical figures
Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.
Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.
Nearby ZIP codes
- 99361 — Waitsburg city, WA (13.3 mi)
- 99329 — Dixie CDP, WA (16.2 mi)
- 99347 — Pomeroy city, WA (17.4 mi)
- 99359 — Starbuck town, WA (21.5 mi)
- 99362 — Walla Walla city, WA (24.4 mi)
Areas that include 99328
- Dayton, WA ZIP codes — 1 ZIP code
- Columbia County ZIP codes — 3 ZIP codes
- Washington ZIP code data
Mail every home in 99328
Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.
EDDM guides
ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 99328, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 99328 in?
- 99328 is a Dayton, WA mailing address. None of its land lies inside a Census-defined city or community.
- What county is 99328 in?
- 99328 is in Columbia County.
- What is the population of 99328?
- About 3,646 people (±126), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 3,620.
- What is the median household income in 99328?
- $72,756 (±$5,984), compared with $98,141 for Washington as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 99328?
- 5 USPS carrier routes with 1,640 residential and 160 business mailboxes (1,801 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 99328?
- The closest, measured center to center: 99361 (13.3 mi, Waitsburg), 99329 (16.2 mi, Dixie), 99347 (17.4 mi, Pomeroy), 99359 (21.5 mi, Starbuck) and 99362 (24.4 mi, Walla Walla).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.