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

Planting zone for 02639 — Dennis Port, MA

ZIP code 02639 (Dennis Port, Barnstable County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 13 and the first fall frost November 3.

Where ZIP 02639 is

Outlined: the ZIP code area · 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 13
First frostNov 3
2012 zone7a

Was 7a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dennis Port, 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 Dennis Port, MA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 13median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostNovember 3median — 10% chance by Oct 22
Growing season204 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 1 and returns around November 17.

From the NOAA station W Harwich, MA — within 1 mile, elevation 16 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 02639

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 2 – Mar 16
SpinachSow outdoors · Mar 2 – Mar 23
Broccoli, cabbageStart indoors · Feb 2 – Feb 16
Broccoli, cabbageTransplant · Mar 23 – Apr 6
Onion setsPlant outdoors · Mar 16 – Mar 30
PotatoesPlant outdoors · Mar 23 – Apr 6
LettuceSow outdoors · Mar 16 – Mar 30
Carrots, beetsSow outdoors · Mar 23 – Apr 6
TomatoesStart indoors · Feb 16 – Mar 2
TomatoesTransplant · Apr 20 – May 4
Peppers, eggplantStart indoors · Feb 2 – Feb 16
Peppers, eggplantTransplant · Apr 27 – May 11
BeansSow outdoors · Apr 20 – May 4
Sweet cornSow outdoors · Apr 20 – May 4
Cucumbers, squashSow outdoors · Apr 20 – May 4
Fall lettuce, spinachSow outdoors · Sep 8 – Sep 22
GarlicPlant cloves · Oct 20 – Nov 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Nov 3) 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 02639 came on Apr 6 — about the same time as the 1991–2020 average (Apr 6).

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 7b in Massachusetts

563 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 7b. Each links to its USDA PLANTS profile.

Trees 67

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 110

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 194

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 165

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 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °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 °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 Dennis Port, MA.

Soil in Dennis Port, MA

The soil mapped at the center of ZIP 02639 is Berryland — loamy coarse sand, very poorly drained.

TextureLoamy coarse sanddrains and warms fast; dries out and needs more feeding
pH4.0strongly acidic; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter6%high
Hydrologic groupA/Ddrains fast once dried out; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Berryland mucky loamy coarse sand, 0 to 2 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 02639; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dennis Port, MA

Summer high78 °Faverage high, July
Winter low24 °Faverage low, February
Hot days1days a year at 90 °F or more
Freezing nights94nights a year at 32 °F or less
Growing degree days2,502base 50 °F — the season’s usable heat
Longest day15 h 12 mindaylight on June 21
Shortest day9 h 09 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation46.3 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 38 °F, low 25 °F 38°25° JanFebruary: average high 38 °F, low 24 °F 38°24° FebMarch: average high 44 °F, low 30 °F 44°30° MarApril: average high 52 °F, low 39 °F 52°39° AprMay: average high 62 °F, low 48 °F 62°48° MayJune: average high 71 °F, low 58 °F 71°58° JunJuly: average high 78 °F, low 65 °F 78°65° JulAugust: average high 78 °F, low 64 °F 78°64° AugSeptember: average high 71 °F, low 57 °F 71°57° SepOctober: average high 62 °F, low 47 °F 62°47° OctNovember: average high 52 °F, low 37 °F 52°37° NovDecember: average high 43 °F, low 30 °F 43°30° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.84 in precipitation 3.8 JanFebruary: 3.68 in precipitation 3.7 FebMarch: 4.32 in precipitation 4.3 MarApril: 4.10 in precipitation 4.1 AprMay: 3.50 in precipitation 3.5 MayJune: 3.29 in precipitation 3.3 JunJuly: 2.77 in precipitation 2.8 JulAugust: 3.36 in precipitation 3.4 AugSeptember: 3.93 in precipitation 3.9 SepOctober: 4.72 in precipitation 4.7 OctNovember: 4.00 in precipitation 4.0 NovDecember: 4.83 in precipitation 4.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: W Harwich, MA (within 1 mile); precipitation: W Harwich, MA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

026717b
West Harwich, MA · 1 mi
026707b
West Dennis, MA · 2 mi
026607a
South Dennis, MA · 3 mi
026647a
South Yarmouth, MA · 3 mi
026467b
Harwich Port, MA · 3 mi
026457b
Harwich, MA · 5 mi
026387b
Dennis, MA · 5 mi
026757a
Yarmouth Port, MA · 5 mi

Massachusetts planting zones →

Questions about 02639

What planting zone is ZIP code 02639?

ZIP code 02639 (Dennis Port, MA) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Dennis Port, MA?

The median last spring frost (32 °F) near 02639 is April 13; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, W Harwich station.

When is the first frost in Dennis Port, MA?

The median first fall frost near 02639 is November 3, giving a median frost-free growing season of 204 days.

When should I plant tomatoes in 02639?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 02639 get?

About 46.3 inches of precipitation a year (NOAA 1991–2020 normals, W Harwich station).

How hot do summers get in Dennis Port, MA?

The average high peaks at 78 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 02639 have?

The USDA soil survey maps Berryland at the center of ZIP 02639: loamy coarse sand, very poorly drained, pH about 4.0 (strongly acidic).

Did spring come early in Dennis Port, MA in 2026?

Spring leaf-out near 02639 came on Apr 6 in 2026, about the same as the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dennis Port, MA?

Long-day onions: the longest day near 02639 is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 02639 change?

Yes. The 2012 USDA map put 02639 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.