When to plant in Somersworth, NH
USDA Zone 6aSomersworth, New Hampshire frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 6a, Somersworth gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
ROCHESTER SKYHAVEN AP · 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 Somersworth’s own odds, recorded at ROCHESTER SKYHAVEN AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 25 | May 12 | May 1 | Sep 17 | Sep 30 | Oct 12 |
| 32°F | May 13 | Apr 30 | Apr 18 | Sep 27 | Oct 9 | Oct 25 |
| 28°F | Apr 29 | Apr 17 | Apr 4 | Oct 7 | Oct 23 | Nov 7 |
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 Somersworth, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 13 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.
Somersworth planting FAQ
When is the last spring frost in Somersworth, NH?
Plan for the last spring frost in Somersworth around April 30 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Somersworth, NH?
The first fall frost in Somersworth typically arrives around October 9 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Somersworth in?
Somersworth 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 Somersworth?
Somersworth has about 162 frost-free days — a moderate growing season — between the average last spring frost (April 30) and first fall frost (October 9).
When should I plant tomatoes in Somersworth?
For Somersworth, sow tomatoes indoors about March 5–March 19 and move the seedlings out around May 7, after the last spring frost.
Never miss a window in Somersworth
An email when it’s time to start seeds, transplant, and sow — timed to Somersworth’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at ROCHESTER SKYHAVEN AP, 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 Somersworth, NH — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00054791. Retrieved from https://blissgarden.com/new-hampshire/somersworth.