When to plant in Dover, NH
USDA Zone 6aDover, New Hampshire frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 6a means Dover sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
DURHAM 2 N · 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 Dover’s own odds, recorded at DURHAM 2 N.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 28 | May 15 | May 4 | Sep 17 | Sep 29 | Oct 11 |
| 32°F | May 16 | May 3 | Apr 23 | Sep 27 | Oct 10 | Oct 25 |
| 28°F | May 3 | Apr 20 | Apr 6 | Oct 7 | Oct 23 | Nov 6 |
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 Dover, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 10 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.
Dover planting FAQ
When is the last spring frost in Dover, NH?
On average, the last spring frost in Dover is around May 3 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Dover, NH?
Expect Dover's first fall frost near October 10 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Dover in?
Dover 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 Dover?
There are roughly 160 frost-free days in Dover (a moderate growing season), running from the average last frost around May 3 to the first fall frost near October 10.
When should I plant tomatoes in Dover?
In Dover, start tomato seeds indoors around March 8–March 22, then transplant seedlings outdoors around May 10 once the danger of frost has passed.
Never miss a window in Dover
An email when it’s time to start seeds, transplant, and sow — timed to Dover’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Durham · 6 km
- Somersworth · 7 km
- Rochester · 15 km
- Portsmouth · 16 km
- Hampton · 27 km
- Sanford · 28 km
- Amesbury · 38 km
- Newburyport · 42 km
Frost dates recorded at DURHAM 2 N, 4 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 Dover, NH — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00054794. Retrieved from https://blissgarden.com/new-hampshire/dover.