USDA zone 7a in Massachusetts
USDA plant hardiness zone 7a covers 15 locations across Massachusetts (average annual extreme minimum 0 to 5 °F): Barnstable, MA, Beverly, MA, Boston, MA, Boston, MA, Duxbury, MA, East Falmouth, MA, and 9 more. Average last spring frost across this group ranges April 4 (Boston) to May 7 (Falmouth), and growing seasons run 156–218 days (Falmouth to Boston) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Massachusetts location's own frost dates; the printable planting calendar uses Boston, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Apr 4–May 7avg, 32°F
- First frost range
- Oct 9–Nov 11avg, 32°F
- Growing season range
- 156–218days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Barnstable | East Sandwich, Mashpee Neck | Hyannis | Apr 16 | Oct 30 | 195 |
| Beverly | Lynn, Marblehead, Swampscott, Nahant | Marblehead | Apr 25 | Oct 20 | 176 |
| Boston * | Brookline | Jamaica Plain | Apr 19 | Oct 23 | 185 |
| Boston | Cambridge, Revere, Somerville, Everett, Chelsea | Boston Logan Intl Ap | Apr 4 | Nov 9 | 218 |
| Duxbury | — | Plymouth-kingston | Apr 15 | Nov 1 | 198 |
| East Falmouth | — | Woods Hole Golf Club | Apr 11 | Nov 11 | 213 |
| Fall River | Somerset, West Wareham | Rochester | Apr 23 | Oct 21 | 180 |
| Fall River | New Bedford, Somerset, North Westport, Mattapoisett Center, Smith Mills, Bliss Corner, +1 more | New Bedford Muni Ap | Apr 29 | Oct 15 | 167 |
| Falmouth | Oak Bluffs, Vineyard Haven | Vineyard Haven Ap | May 7 | Oct 9 | 156 |
| Gloucester | Rockport | Beverly Muni Ap | Apr 24 | Oct 17 | 177 |
| Kingston | The Pinehills | Plymouth Muni Ap | Apr 30 | Oct 16 | 170 |
| North Falmouth | Forestdale, West Wareham, Pocasset, Sandwich, Sagamore, Monument Beach, +5 more | E Wareham | Apr 21 | Oct 24 | 186 |
| North Westport | Tiverton, Ocean Grove | Tiverton | Apr 11 | Nov 2 | 203 |
| South Yarmouth | West Yarmouth, Yarmouth Port, South Dennis | Hyannis Barnstable Muni Ap | Apr 22 | Oct 28 | 188 |
| Weymouth | Quincy, Marshfield, Marshfield Hills, North Scituate, Hingham | Hingham | Apr 25 | Oct 22 | 177 |
* Boston is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Boston, representative)
Computed from Boston's average frost dates — the median-season location in this Massachusettszone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 22 – Mar 8 | Apr 26 – May 3 | Jun 25 – Jul 15 | — | matures comfortably |
| Pepper | Very tender | Feb 8 – Feb 22 | May 3 – May 10 | Jul 2 – Aug 1 | — | matures comfortably |
| Cucumber | Tender | Mar 22 – Mar 29 | Apr 26 – May 3 | Jun 15 – Jul 5 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 26 – May 3 | Jun 10 – Jun 25 | — | matures comfortably |
| Bush bean | Tender | — | Apr 26 – May 3 | Jun 15 – Jun 25 | Aug 24 – Sep 3 | matures comfortably |
| Sweet corn | Tender | — | Apr 19 – May 3 | Jun 18 – Jul 18 | — | matures comfortably |
| Basil | Very tender | Mar 8 – Mar 22 | Apr 26 – May 3 | May 26 – Jun 10 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 8 – Mar 22 | Mar 22 – Apr 5 | May 6 – May 21 | Aug 10 – Aug 25 | matures comfortably |
| Pea | Hardy | — | Mar 8 – Mar 22 | May 2 – May 17 | Jul 31 – Aug 15 | matures comfortably |
| Spinach | Hardy | — | Mar 8 – Mar 22 | Apr 17 – Apr 27 | Aug 20 – Aug 30 | matures comfortably |
| Carrot | Half-hardy | — | Mar 29 – Apr 5 | May 28 – Jun 17 | Jul 21 – Aug 10 | matures comfortably |
| Broccoli | Half-hardy | Feb 22 – Mar 8 | Mar 22 – Apr 5 | May 16 – Jun 5 | Jul 26 – Aug 15 | matures comfortably |
Which crops fit this growing season
Using Boston's own 185-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Boston)
From NOAA's 1991–2020 Climate Normals at station USC00193890. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 2 | May 16 | Oct 10 | Oct 25 | 161 |
| 32°F (freeze) | Apr 19 | May 3 | Oct 23 | Nov 5 | 185 |
| 28°F | Apr 5 | Apr 21 | Nov 3 | Nov 19 | 210 |
| 24°F | Mar 28 | Apr 7 | Nov 15 | Dec 3 | 233 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 15 locations is 2,752; Boston's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,047 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,269 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Massachusetts
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Massachusetts spans 5 hardiness zones in this dataset — see all Massachusetts locations for the full range, including zones5b, 6a, 6b, 7b.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Massachusetts?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 15 locations in Massachusetts fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Massachusetts's zone 7a is the growing season longest?
- Boston runs the longest season on this page at about 218 days; Falmouth is shortest at about 156 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Massachusetts's zone 7a?
- Using Boston's frost dates (this page's median-season location): start seeds indoors about Feb 22 – Mar 8, then transplant outside about Apr 26 – May 3. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Massachusetts's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 15 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.