In which county is ZIP code 99328 located?

ZIP 99328 is listed under Columbia, WA.

When was this page updated?

This page was updated on 2026-01-08.

ZIP Code 99328: Dayton, WA

ZIP: 99328

County: Columbia

Coordinates: 46.30750, -117.97380

ZIP Type: Standard

Time Zone: Pacific Time (PT)

Get a reliable snapshot of the Dayton, WA postal area 99328. This page summarizes county, coordinates, and local facts to help with services and location research.

Primary City	Dayton
ZIP Code	99328
County	Columbia
State	WA
Latitude / Longitude	46.30750, -117.97380
ZIP Type	Standard
Time Zone	Pacific Time (PT)
Data Updated	2026-01-08

Maps & Useful Links

Open in Maps: Google Maps · OpenStreetMap

These links show the approximate center point for ZIP 99328 (not an exact boundary).

Geographic & Administrative Context

Coordinates for 99328 are listed as 46.30750 / -117.97380, useful for GPS and service checks in and around Dayton, WA.

Local Coverage Notes

ZIP codes can cover multiple neighborhoods and unincorporated areas. Use ZIP 99328 for mail delivery and general location reference in Columbia, WA.

Coverage may include nearby neighborhoods and adjacent unincorporated areas commonly associated with Dayton.

Related ZIP Codes (Nearby)

Explore other postal codes near Dayton within WA.

Frequently Asked Questions

What is the primary city for ZIP code 99328?

The primary city for this ZIP code is Dayton, located in WA.

In which county is 99328 located?

ZIP code 99328 is situated within Columbia, WA.

What are the coordinates for 99328?

The approximate center point is 46.30750 (Latitude) and -117.97380 (Longitude).

Is ZIP code 99328 active?

This page lists ZIP 99328 as Listed based on the latest refresh date shown above.

Does ZIP 99328 cover multiple areas?

Yes. Many ZIP codes cover multiple neighborhoods or nearby areas. For exact boundaries, use official mapping tools.

Methodology & Data Notes

How we build this page: We generate this page from a structured ZIP dataset and refresh key fields (city, county, and coordinates) during scheduled updates. Coordinates represent an approximate center point, not an official boundary map.
Sources: Public ZIP reference datasets and geographic coordinate references. If you use specific sources (e.g., USPS, Census), list them on your About/Methodology page.

Page updated: 2026-01-08