ZIP Code 06378

06378 is one of Connecticut's ZIP codes, delivering to addresses in Stonington, Southeastern Connecticut Planning Region.

City

Stonington

Planning region

Southeastern Connecticut Planning Region

State

Connecticut

Prefix

063xx

Where this code sits

06378 is part of the 063xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Stonington.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 06378 delivers to without sharing its boundary.

ZIP codes nearest 06378

The ZIP codes whose reference points sit closest to 06378.
ZIP code	Distance	Delivers to
ZIP code 06372	2.3 mi	Old Mystic, CT
ZIP code 06355	3.2 mi	Mystic, CT
ZIP code 06388	3.5 mi	West Mystic, CT
ZIP code 06379	3.5 mi	Pawcatuck, CT
ZIP code 02891	5.3 mi	Westerly, RI
ZIP code 06359	6.4 mi	North Stonington, CT
ZIP code 06339	6.6 mi	Ledyard, CT
ZIP code 06340	7.4 mi	Groton, CT

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 06378, plotted from its record coordinates.

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

Scope ZIP code 06378. 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.