ZIP Code 15642

15642 is one of Pennsylvania's ZIP codes, delivering to addresses in Irwin, Westmoreland County.

City: Irwin
County: Westmoreland County
State: Pennsylvania
Prefix: 156xx

Where this code sits

15642 is part of the 156xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Irwin.

Irwin Pennsylvania ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 15642 delivers to without sharing its boundary.

ZIP codes nearest 15642

The ZIP codes whose reference points sit closest to 15642.
ZIP code	Distance	Delivers to
ZIP code 15647	1.8 mi	Larimer, PA
ZIP code 15692	2.2 mi	Westmoreland City, PA
ZIP code 15678	2.2 mi	Rillton, PA
ZIP code 15691	2.5 mi	Wendel, PA
ZIP code 15615	2.8 mi	Ardara, PA
ZIP code 15665	2.9 mi	Manor, PA
ZIP code 15611	3.4 mi	Adamsburg, PA
ZIP code 15675	4.2 mi	Penn, PA

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 15642, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 15642. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.