ZIP code · Newmarket · New Hampshire · United States
ZIP code 03857 — Newmarket
ZIP code 03857 serves Newmarket, New Hampshire.
- Postal code
- 03857Single source Value from one source, not cross-checked.
- City
- Newmarket
- County
- Rockingham FIPS 33015
- State
- New Hampshire
- Country
- United States
- Coordinates
- 43.0726, -70.9553 — precision precise (locality)
View on OpenStreetMap - Population
- 9,431 (ZCTA, ACS 5-year)
- Population density
- 749 / sq mi
- Land area
- 12.6 sq mi (32.6 km²) (ZCTA, ACS 5-year)
- Median household income
- $94,345
- Per-capita income
- $54,210
- Median age
- 39.3
- Households
- 4,313
- Housing units
- 4,443
- Median home value
- $384,900
- Median gross rent
- $1,648 / month
- Congressional district
- NH-1 (119th Congress)
- USDA hardiness zone
- 6a (-10 to -5 °F)Planting / growing zone from the 2023 USDA Plant Hardiness Zone Map: average annual extreme minimum temperature, 1991–2020.
- Time zone
- America/New_York (UTC−5 / UTC−4 DST)
- Area code
- 603Telephone area codes serving this ZIP (NANPA central-office assignments). A ZIP and an area code are different boundaries; at a border both codes may apply.
Tools: compare 03857 with another ZIP · ZIPs within 25 miles · distance from 03857
Nearby localities
Map of ZIP code 03857
Climate — monthly normals
Warmest month Jul (avg high 81°F), coldest Jan (avg low 14°F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 36 | 44 | 56 | 67 | 76 | 81 | 80 | 72 | 60 | 48 | 38 |
| Avg low °F | 14 | 16 | 24 | 34 | 43 | 53 | 58 | 57 | 49 | 39 | 29 | 21 |
| Precip in | 3.4 | 3.5 | 4.6 | 4.0 | 3.8 | 4.0 | 3.7 | 3.5 | 4.0 | 4.3 | 4.0 | 4.4 |
NOAA 1991–2020 climate normals from the nearest station: DURHAM 2 SSW (2.5 mi) · NOAA NCEI
Places in ZIP 03857
- 2 schools
- 3 doctors & dentists
- 1 supermarkets
- 21 restaurants & cafés
- 3 bars & pubs
- 6 parks
- 8 playgrounds
- 2 gyms & sports centres
- 1 libraries
- 1 post offices
- 3 places of worship
- 2 banks
- 3 gas stations
- 3 EV charging stations
- 2 police & fire stations
Places mapped inside this ZIP’s ZCTA area in OpenStreetMap. OSM is community-maintained: counts reflect what has been mapped, and completeness varies by area — treat them as at-least figures. © OpenStreetMap contributors (ODbL) · Methodology
About this page
US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.
GeoNames · U.S. Census Bureau (ACS) · U.S. Census Bureau · NOAA NCEI · usda-phzm. Data generated on 2026-08-21. Methodology · Report an error on this page