Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Boston, MA

Boston, MA is in USDA zones 6b to 7a across its 34 ZIP codes. The median last spring frost is April 4 and the first fall frost November 9.

Boston on the zone map

Outlined: its 17 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zones6b–7a−5 to 5 °F

ZIP codes34

Last frostApr 4

First frostNov 9

Growing season218 days

6b 2 ZIPs 7a 32 ZIPs

Frost forecast — next 7 nights

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Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Boston, MA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 4median — 50% chance of a later frost

Safe for tender plantsApril 17only 10% chance of frost after

First fall frostNovember 9median — 10% chance by Oct 29

Growing season218 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 28 and returns around November 21.

From the NOAA station Boston Logan Intl Airport, MA, elevation 13 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Boston

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 21 – Mar 7

SpinachSow outdoors · Feb 21 – Mar 14

Broccoli, cabbageStart indoors · Jan 24 – Feb 7

Broccoli, cabbageTransplant · Mar 14 – Mar 28

Onion setsPlant outdoors · Mar 7 – Mar 21

PotatoesPlant outdoors · Mar 14 – Mar 28

LettuceSow outdoors · Mar 7 – Mar 21

Carrots, beetsSow outdoors · Mar 14 – Mar 28

TomatoesStart indoors · Feb 7 – Feb 21

TomatoesTransplant · Apr 11 – Apr 25

Peppers, eggplantStart indoors · Jan 24 – Feb 7

Peppers, eggplantTransplant · Apr 18 – May 2

BeansSow outdoors · Apr 11 – Apr 25

Sweet cornSow outdoors · Apr 11 – Apr 25

Cucumbers, squashSow outdoors · Apr 11 – Apr 25

Fall lettuce, spinachSow outdoors · Sep 14 – Sep 28

GarlicPlant cloves · Oct 26 – Nov 30

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 4) and first fall frost (Nov 9) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 02210 came on Mar 31 — about the same time as the 1991–2020 average (Apr 2).

average
Apr 22026
Mar 31

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in Boston, MA

The center of ZIP 02210 is mapped as Urban land, wet substratum, 0 to 3 percent slopes: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 02210; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Boston, MA

Summer high82 °Faverage high, July

Winter low23 °Faverage low, January

Hot days14days a year at 90 °F or more

Freezing nights92nights a year at 32 °F or less

Growing degree days3,050base 50 °F — the season’s usable heat

Longest day15 h 17 mindaylight on June 21

Shortest day9 h 04 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation43.6 inper year, rain and melted snow

Snowfall49 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Boston Logan Intl Airport, MA (2 mi away); precipitation: Boston Logan Intl Airport, MA (2 mi away). Daylight is calculated from latitude.

Questions about Boston

What planting zone is Boston, MA?

Boston, MA is in USDA hardiness zones 6b to 7a on the 2023 map (6b: −5 to 0 °F; 7a: 0 to 5 °F).

When is the last frost in Boston, MA?

The median last spring frost is April 4 and the median first fall frost is November 9 (NOAA 1991–2020 normals, Boston Logan Intl Airport station).

When can I plant a garden in Boston, MA?

Cool-season crops like peas and spinach go in around Feb 21 – Mar 14; tomatoes, peppers, beans and squash after about Apr 11, once frost risk has passed.

What kind of onions grow in Boston, MA?

Long-day onions: the longest day is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Boston, MA get?

About 43.6 inches of precipitation a year and 49 inches of snowfall (NOAA 1991–2020 normals).