When to plant in Somerville, MA
USDA Zone 7aEverything below — frost dates, hardiness zone, and what to plant when in Somerville, Massachusetts — is derived from the closest NOAA station with complete climate normals.
In zone 7a, Somerville supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
BOSTON LOGAN INTL 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 Somerville’s own odds, recorded at BOSTON LOGAN INTL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 1 | Apr 17 | Apr 6 | Oct 15 | Oct 29 | Nov 11 |
| 32°F | Apr 17 | Apr 4 | Mar 25 | Oct 29 | Nov 9 | Nov 22 |
| 28°F | Apr 6 | Mar 28 | Mar 15 | Nov 8 | Nov 21 | Dec 5 |
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 Somerville, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Somerville planting FAQ
When is the last spring frost in Somerville, MA?
Plan for the last spring frost in Somerville around April 4 (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 Somerville, MA?
The first fall frost in Somerville typically arrives around November 9 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Somerville in?
Somerville is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Somerville?
Somerville has about 219 frost-free days — a long growing season — between the average last spring frost (April 4) and first fall frost (November 9).
When should I plant tomatoes in Somerville?
For Somerville, sow tomatoes indoors about February 7–February 21 and move the seedlings out around April 11, after the last spring frost.
Never miss a window in Somerville
An email when it’s time to start seeds, transplant, and sow — timed to Somerville’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at BOSTON LOGAN INTL AP, 8 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 Somerville, MA — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014739. Retrieved from https://blissgarden.com/massachusetts/somerville.