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

Planting zone for 02027 — Dedham, MA

ZIP code 02027 (Dedham, Norfolk County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 18 and the first fall frost October 26.

Where ZIP 02027 is

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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 18
First frostOct 26
2012 zone6b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dedham, MA…

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 Dedham, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostOctober 26median — 10% chance by Oct 9
Growing season190 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around November 5.

From the NOAA station Blue Hill Coop, MA — 2 miles away, elevation 627 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 02027

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14
GarlicPlant cloves · Oct 12 – Nov 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 26) 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 02027 came on Apr 3 — 4 days earlier than the 1991–2020 average (Apr 7).

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).

Native plants for zone 6b in Massachusetts

548 plants native to the lower 48 states, recorded in Massachusetts, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 66

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 109

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 188

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 159

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °F

Vines 8

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Dedham, MA.

Soil in Dedham, MA

The soil mapped at the center of ZIP 02027 is Freetown — mucky peat, very poorly drained.

TextureMucky peattop layer
DrainageVery poorly drainedconsider raised beds
Organic matter82%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Freetown muck, 0 to 1 percent slopes.

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 02027; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dedham, MA

Summer high82 °Faverage high, July
Winter low18 °Faverage low, January
Hot days9days a year at 90 °F or more
Freezing nights121nights a year at 32 °F or less
Growing degree days2,799base 50 °F — the season’s usable heat
Longest day15 h 16 mindaylight on June 21
Shortest day9 h 06 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation53.9 inper year, rain and melted snow
Snowfall70 inper year; 56 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 18 °F 35°18° JanFebruary: average high 37 °F, low 20 °F 37°20° FebMarch: average high 44 °F, low 27 °F 44°27° MarApril: average high 56 °F, low 38 °F 56°38° AprMay: average high 67 °F, low 48 °F 67°48° MayJune: average high 75 °F, low 58 °F 75°58° JunJuly: average high 82 °F, low 64 °F 82°64° JulAugust: average high 80 °F, low 63 °F 80°63° AugSeptember: average high 73 °F, low 56 °F 73°56° SepOctober: average high 61 °F, low 44 °F 61°44° OctNovember: average high 50 °F, low 34 °F 50°34° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 4.50 in precipitation, 18.6 in snowfall 4.5❄19 JanFebruary: 4.00 in precipitation, 18.2 in snowfall 4.0❄18 FebMarch: 5.52 in precipitation, 15 in snowfall 5.5❄15 MarApril: 4.76 in precipitation, 2.8 in snowfall 4.8❄3 AprMay: 3.82 in precipitation 3.8 MayJune: 4.63 in precipitation 4.6 JunJuly: 3.47 in precipitation 3.5 JulAugust: 3.91 in precipitation 3.9 AugSeptember: 4.06 in precipitation 4.1 SepOctober: 5.49 in precipitation, 0.7 in snowfall 5.5❄1 OctNovember: 4.31 in precipitation, 1.8 in snowfall 4.3❄2 NovDecember: 5.39 in precipitation, 12.6 in snowfall 5.4❄13 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Blue Hill Coop, MA (2 mi away); precipitation: Blue Hill Coop, MA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

021856b
Braintree, MA · <1 mi
023686b
Randolph, MA · 2 mi
020216b
Canton, MA · 2 mi
023226b
Avon, MA · 4 mi
021866b
Milton, MA · 4 mi
020726b
Stoughton, MA · 4 mi
021846b
Braintree, MA · 5 mi
021376b
Readville, MA · 5 mi

All 2 ZIP codes in Dedham → · Massachusetts planting zones →

Questions about 02027

What planting zone is ZIP code 02027?

ZIP code 02027 (Dedham, MA) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Dedham, MA?

The median last spring frost (32 °F) near 02027 is April 18; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blue Hill Coop station.

When is the first frost in Dedham, MA?

The median first fall frost near 02027 is October 26, giving a median frost-free growing season of 190 days.

When should I plant tomatoes in 02027?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 02027 get?

About 53.9 inches of precipitation a year and 70 inches of snowfall (NOAA 1991–2020 normals, Blue Hill Coop station).

How hot do summers get in Dedham, MA?

The average high peaks at 82 °F in July, with about 9 days a year at 90 °F or more.

What kind of soil does 02027 have?

The USDA soil survey maps Freetown at the center of ZIP 02027: mucky peat, very poorly drained.

Did spring come early in Dedham, MA in 2026?

Spring leaf-out near 02027 came on Apr 3 in 2026, 4 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dedham, MA?

Long-day onions: the longest day near 02027 is 15 h 16 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).