In which county is ZIP code 03857 located?

ZIP 03857 is listed under Rockingham, NH.

When was this page updated?

This page was updated on 2026-01-08.

ZIP Code 03857: Newmarket, NH

ZIP: 03857

County: Rockingham

Coordinates: 43.07260, -70.95530

ZIP Type: Standard

Time Zone: Eastern Time (ET)

This profile provides an in-depth look at ZIP code 03857, serving Newmarket in NH. It lies in Rockingham and supports delivery, planning, and address verification.

Primary City	Newmarket
ZIP Code	03857
County	Rockingham
State	NH
Latitude / Longitude	43.07260, -70.95530
ZIP Type	Standard
Time Zone	Eastern Time (ET)
Data Updated	2026-01-08

Maps & Useful Links

Open in Maps: Google Maps · OpenStreetMap

These links show the approximate center point for ZIP 03857 (not an exact boundary).

Geographic & Administrative Context

For mapping and verification, 03857 is commonly represented around 43.07260, -70.95530. These coordinates help identify the general area within Rockingham, NH.

Local Coverage Notes

ZIP codes can cover multiple neighborhoods and unincorporated areas. Use ZIP 03857 for mail delivery and general location reference in Rockingham, NH.

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

Related ZIP Codes (Nearby)

Explore other postal codes near Newmarket within NH.

Frequently Asked Questions

What is the primary city for ZIP code 03857?

The primary city for this ZIP code is Newmarket, located in NH.

In which county is 03857 located?

ZIP code 03857 is situated within Rockingham, NH.

What are the coordinates for 03857?

The approximate center point is 43.07260 (Latitude) and -70.95530 (Longitude).

Is ZIP code 03857 active?

This page lists ZIP 03857 as Listed based on the latest refresh date shown above.

Does ZIP 03857 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