Thornton New Hampshire ZIP Codes

Thornton holds a single ZIP code.

Every ZIP code in Thornton

The complete list of Thornton, New Hampshire ZIP codes with the county each falls in.
ZIP code	County
03285	Grafton 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We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Thornton codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Thornton. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

How these codes cluster

Every Thornton ZIP code begins 032. Those first three digits identify the sectional center facility that processes mail for this part of New Hampshire. Statewide that range covers 64 ZIP codes, so Thornton accounts for 2% of it.

Every New Hampshire ZIP prefix and the region it covers →

Area codes covering Thornton

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 Thornton occupies.

603 Area code 603

These codes are associated with Thornton through county-level matching, not a per-address guarantee.

Thornton New Hampshire area codes in full →

Where Thornton's ZIP codes sit

Each point is one Thornton ZIP code, plotted from its record coordinates.

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

Cities near Thornton

The closest places to Thornton with their own ZIP code list, nearest first.
City	Distance	ZIP codes
Campton New Hampshire ZIP codes	4.5 mi	1 ZIP code
Lincoln New Hampshire ZIP codes	11 mi	1 ZIP code
Holderness New Hampshire ZIP codes	12 mi	1 ZIP code
Plymouth New Hampshire ZIP codes	12 mi	1 ZIP code
Ashland New Hampshire ZIP codes	15 mi	1 ZIP code
Moultonborough New Hampshire ZIP codes	18 mi	1 ZIP code
Meredith New Hampshire ZIP codes	19 mi	1 ZIP code
Bristol New Hampshire ZIP codes	21 mi	1 ZIP code

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