When to plant in Durham, NH
USDA Zone 6aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Durham, New Hampshire — all computed from Durham's nearest NOAA weather station.
In zone 6a, Durham gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
DURHAM · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Durham’s own odds, recorded at DURHAM.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 2 | May 20 | May 7 | Sep 12 | Sep 26 | Oct 6 |
| 32°F | May 22 | May 8 | Apr 27 | Sep 23 | Oct 4 | Oct 20 |
| 28°F | May 10 | Apr 27 | Apr 13 | Oct 2 | Oct 15 | Nov 2 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Durham, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 4 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Durham planting FAQ
When is the last spring frost in Durham, NH?
Durham's average last spring frost falls near May 8 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Durham, NH?
The first fall frost in Durham typically arrives around October 4 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Durham in?
Durham is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Durham?
Durham has about 149 frost-free days — a short growing season — between the average last spring frost (May 8) and first fall frost (October 4).
When should I plant tomatoes in Durham?
For Durham, sow tomatoes indoors about March 13–March 27 and move the seedlings out around May 15, after the last spring frost.
Never miss a window in Durham
An email when it’s time to start seeds, transplant, and sow — timed to Durham’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Dover · 6 km
- Somersworth · 13 km
- Portsmouth · 15 km
- Rochester · 18 km
- Hampton · 24 km
- Amesbury · 33 km
- Sanford · 34 km
- Newburyport · 37 km
Frost dates recorded at DURHAM, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Durham, NH — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00272174. Retrieved from https://blissgarden.com/new-hampshire/durham.