Dayton Washington ZIP Codes
Dayton holds a single ZIP code.
Every ZIP code in Dayton
| ZIP code | County |
|---|---|
| 99328 | Columbia County |
We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Dayton codes above are listed without a column we would have to invent.
Scope every ZIP code recorded for Dayton. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated . ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.
How these codes cluster
Every Dayton ZIP code begins 993. Those first three digits identify the sectional center facility that processes mail for this part of Washington. Statewide that range covers 36 ZIP codes, so Dayton accounts for 3% of it.
Every Washington ZIP prefix and the region it covers →
Area codes covering Dayton
ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The code below serves the same ground Dayton occupies.
Dayton Washington area codes in full →
Where Dayton's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Cities near Dayton
| City | Distance | ZIP codes |
|---|---|---|
| Waitsburg Washington ZIP codes | 8.9 mi | 1 ZIP code |
| Starbuck Washington ZIP codes | 16 mi | 1 ZIP code |
| Prescott Washington ZIP codes | 16 mi | 1 ZIP code |
| Pomeroy Washington ZIP codes | 21 mi | 1 ZIP code |
| Walla Walla Washington ZIP codes | 24 mi | 1 ZIP code |
| College Place Washington ZIP codes | 28 mi | 1 ZIP code |
| Lacrosse Washington ZIP codes | 33 mi | 1 ZIP code |
| Washtucna Washington ZIP codes | 34 mi | 1 ZIP code |
Straight-line distance between place reference points, not driving distance.