Deconstruct SunNew Hampshire Hardiness Zones
New Hampshire covers USDA plant hardiness zones 4a to 6b on the 2023 map, so its coldest areas average −30 to −25 °F on the coldest winter night. Find your zone by ZIP code, or pick a city below for its zone, sunrise and daylight by month.
New Hampshire hardiness zone map
This is not the official USDA Plant Hardiness Zone Map. Zones are derived from the official 2023 dataset, resampled to about 2 km. Dots mark cities with their own page.
Source: USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture, planthardiness.ars.usda.gov. Underlying data © PRISM Group, Oregon State University, prism.oregonstate.edu, accessed 2026-08-30.
Zones and daylight by city
| City | Zone | Coldest night | Longest day | Shortest day |
|---|---|---|---|---|
| Manchester | 6a | −10 to −5 °F | 15h 22m | 9h 00m |
| Nashua | 6a | −10 to −5 °F | 15h 20m | 9h 02m |
| Concord | 5b | −15 to −10 °F | 15h 24m | 8h 59m |
| Portsmouth | 6a | −10 to −5 °F | 15h 22m | 9h 00m |
Gardening in New Hampshire?
Your zone says what survives winter. Deconstruct Sun measures how many hours of direct sun your exact spot gets, so you can pick plants that thrive. Free on iPhone.
Questions
What hardiness zones are in New Hampshire?
New Hampshire spans USDA zones 4a to 6b on the 2023 map. Among its larger cities, Concord is coldest (zone 5b) and Manchester is warmest (zone 6a).
How do I find my exact zone in New Hampshire?
Enter your ZIP code in the hardiness zone lookup on this site. It reads the 2023 USDA data for that ZIP and warns you if you are near a zone boundary.
How much sun do gardens in New Hampshire get?
In Manchester, an open spot gets up to 15.4 hours of daylight in June but only 9.0 in December. Trees and buildings cut that down, especially in winter. The Deconstruct Sun app measures the real direct-sun hours for one exact spot.