Farmington Washington ZIP Codes
Farmington holds a single ZIP code.
Every ZIP code in Farmington
| ZIP code | County |
|---|---|
| 99128 | Whitman 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We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Farmington codes above are listed without a column we would have to invent.
Scope every ZIP code recorded for Farmington. 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 Farmington ZIP code begins 991. Those first three digits identify the sectional center facility that processes mail for this part of Washington. Statewide that range covers 67 ZIP codes, so Farmington accounts for 1% of it.
Every Washington ZIP prefix and the region it covers →
Area codes covering Farmington
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 Farmington occupies.
Farmington Washington area codes in full →
Where Farmington's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Cities near Farmington
| City | Distance | ZIP codes |
|---|---|---|
| Garfield Washington ZIP codes | 7.0 mi | 1 ZIP code |
| Tekoa Washington ZIP codes | 9.5 mi | 1 ZIP code |
| Oakesdale Washington ZIP codes | 9.8 mi | 1 ZIP code |
| Palouse Washington ZIP codes | 12 mi | 1 ZIP code |
| Latah Washington ZIP codes | 14 mi | 1 ZIP code |
| Colfax Washington ZIP codes | 17 mi | 1 ZIP code |
| Rosalia Washington ZIP codes | 19 mi | 1 ZIP code |
| Waverly Washington ZIP codes | 19 mi | 1 ZIP code |
Straight-line distance between place reference points, not driving distance.