USDA hardiness zones — 2023 map
New Hampshire hardiness zones — USDA planting zone map + what to grow
Zones 3b-6a · most of New Hampshire is zone 5b · Northeast region
New HampshireUSDA zone range & map
On the 2023 USDA Plant Hardiness Zone Map, New Hampshire spans zones 3b-6a. The map shades the state from the White Mountains and far north (zone 3b) through to the short Atlantic seacoast near Portsmouth (zone 6a). The single most common half-zone across the populated state is zone 5b — that is the figure to use if you only remember one number for New Hampshire. New Hampshire is a cold New England state with a brief but reliable summer, milder along the small seacoast and colder in the mountains.
| USDA zone range | Zones 3b-6a |
|---|---|
| Most common zone | Zone 5b |
| Coldest area | the White Mountains and far north (zone 3b) |
| Warmest area | the short Atlantic seacoast near Portsmouth (zone 6a) |
| Average last spring frost | mid-May |
| Average first fall frost | late September |
Source: USDA 2023 Plant Hardiness Zone Map (1991-2020 normals). Frost averages: NOAA/NCEI 1991-2020 climate normals. Local ZIP-level zones and frost dates can differ from these statewide figures.
New Hampshire hardiness zones by major city
Zones shift across New Hampshire with elevation and distance from the coast. Here is the 2023 USDA half-zone for the largest cities:
| City | USDA zone |
|---|---|
| Manchester | Zone 5b |
| Concord | Zone 5b |
| Nashua | Zone 5b |
| Portsmouth | Zone 6a |
Need your exact zone? Run the ZIP-code zone finder for a precise half-zone and frost dates for your address.
ZIP-code zones in New Hampshire
Statewide ranges hide a lot. Tap your area for its exact USDA half-zone, last and first frost dates, and what to plant now:
- Derry 03038 — Zone 5b
- Nashua 03060 — Zone 6a
- Manchester 03101 — Zone 5b
- Manchester (North) 03104 — Zone 5b
- Concord 03301 — Zone 5b
- Keene 03431 — Zone 5a
- Portsmouth 03801 — Zone 6a
What New Hampshire's zone range means for planting
Your hardiness zone tells you which perennials, shrubs, and trees will survive a typical New Hampshire winter, and it anchors when tender crops can go outside. Because New Hampshire spans 3b-6a, two gardeners in the same state can have very different planting calendars.
- Pick perennials hardy to your local zone. Across most of New Hampshire that means at least zone 5b; gardeners in the White Mountains and far north (zone 3b) should choose hardier plants.
- Anchor tender crops to your frost dates. With a last spring frost around mid-May and first fall frost around late September, set out tomatoes, peppers, and basil after the last frost and protect them before the first.
- Adjust for your microclimate. Urban heat, a south-facing slope, or a cold valley pocket can shift your effective zone and frost dates by a half-zone or more from the statewide figure.
Find your exact zone in New Hampshire
The 3b-6a range is statewide. Growli pins your hardiness zone and frost dates to your exact ZIP code and sends a push notification before any forecast frost night for your saved location.
Frequently asked questions
What hardiness zone is New Hampshire?
New Hampshire spans USDA hardiness zones 3b-6a on the 2023 USDA Plant Hardiness Zone Map. The most common zone — covering the largest share of the populated state — is zone 5b. The coldest areas are the White Mountains and far north (zone 3b) and the warmest are the short Atlantic seacoast near Portsmouth (zone 6a).
When is the last frost in New Hampshire?
Across most of New Hampshire the average last spring frost falls around mid-May and the first fall frost around late September. These are statewide averages — colder, higher areas run later in spring and earlier in fall, so check a ZIP-level estimate for your exact spot.
What grows well in New Hampshire?
New Hampshire is a cold New England state with a brief but reliable summer, milder along the small seacoast and colder in the mountains. Match plants to your local half-zone within the 3b-6a range: choose varieties hardy to at least zone 5b for reliable overwintering, and time tender crops around your local frost dates. The zone 5 planting guide lists vegetables, fruit, and ornamentals suited to most of the state.
Why does New Hampshire have more than one hardiness zone?
Hardiness zones track the average annual coldest temperature, which changes with latitude, elevation, distance from water, and urban heat. That is why New Hampshire ranges from the White Mountains and far north (zone 3b) to the short Atlantic seacoast near Portsmouth (zone 6a) — a span of 3b-6a — even though it is a single state.
Did New Hampshire's hardiness zone change in 2023?
The USDA updated the Plant Hardiness Zone Map in November 2023 using 1991-2020 climate data. About half the country, including parts of New Hampshire, shifted to the next warmer half-zone versus the 2012 map. The 3b-6a range here reflects the current 2023 map. Always confirm your address against the official USDA map for plant-survival decisions.