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

Planting zone for 04554 — New Harbor, ME

ZIP code 04554 (New Harbor, Lincoln County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 28 and the first fall frost October 21.

Where ZIP 04554 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 28
First frostOct 21
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for New Harbor, ME…

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 New Harbor, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 28median — 50% chance of a later frost
Safe for tender plantsMay 9only 10% chance of frost after
First fall frostOctober 21median — 10% chance by Oct 5
Growing season175 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around November 4.

From the NOAA station Westport Island, ME — 10 miles away, elevation 89 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 04554

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 17 – Mar 31
SpinachSow outdoors · Mar 17 – Apr 7
Broccoli, cabbageStart indoors · Feb 17 – Mar 3
Broccoli, cabbageTransplant · Apr 7 – Apr 21
Onion setsPlant outdoors · Mar 31 – Apr 14
PotatoesPlant outdoors · Apr 7 – Apr 21
LettuceSow outdoors · Mar 31 – Apr 14
Carrots, beetsSow outdoors · Apr 7 – Apr 21
TomatoesStart indoors · Mar 3 – Mar 17
TomatoesTransplant · May 5 – May 19
Peppers, eggplantStart indoors · Feb 17 – Mar 3
Peppers, eggplantTransplant · May 12 – May 26
BeansSow outdoors · May 5 – May 19
Sweet cornSow outdoors · May 5 – May 19
Cucumbers, squashSow outdoors · May 5 – May 19
Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 28) and first fall frost (Oct 21) 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 04554 came on Apr 17 — 5 days earlier than the 1991–2020 average (Apr 22).

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 6a in Maine

502 plants native to the lower 48 states, recorded in Maine, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 55

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 101

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine bearberry0.5 ft · blooms early spring · medium shade tolerance · to −62 °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 °F

Wildflowers & perennials 173

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 154

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican 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 °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 6

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °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 New Harbor, ME.

Soil in New Harbor, ME

The soil mapped at the center of ZIP 04554 is Sheepscot — fine sandy loam, moderately well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH5.1strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Sheepscot fine sandy loam, 0 to 8 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 04554; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in New Harbor, ME

Summer high76 °Faverage high, July
Winter low14 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights148nights a year at 32 °F or less
Growing degree days1,990base 50 °F — the season’s usable heat
Longest day15 h 28 mindaylight on June 21
Shortest day8 h 54 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation50 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 31 °F, low 14 °F 31°14° JanFebruary: average high 33 °F, low 16 °F 33°16° FebMarch: average high 41 °F, low 24 °F 41°24° MarApril: average high 51 °F, low 34 °F 51°34° AprMay: average high 63 °F, low 44 °F 63°44° MayJune: average high 70 °F, low 53 °F 70°53° JunJuly: average high 76 °F, low 59 °F 76°59° JulAugust: average high 76 °F, low 59 °F 76°59° AugSeptember: average high 69 °F, low 51 °F 69°51° SepOctober: average high 58 °F, low 42 °F 58°42° OctNovember: average high 47 °F, low 32 °F 47°32° NovDecember: average high 37 °F, low 22 °F 37°22° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.75 in precipitation 3.8 JanFebruary: 3.64 in precipitation 3.6 FebMarch: 4.33 in precipitation 4.3 MarApril: 4.37 in precipitation 4.4 AprMay: 3.67 in precipitation 3.7 MayJune: 4.53 in precipitation 4.5 JunJuly: 3.40 in precipitation 3.4 JulAugust: 4.04 in precipitation 4.0 AugSeptember: 4.06 in precipitation 4.1 SepOctober: 5.07 in precipitation 5.1 OctNovember: 4.56 in precipitation 4.6 NovDecember: 4.61 in precipitation 4.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Westport Island, ME (10 mi away); precipitation: Westport Island 2.2 Ssw, ME (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

045586a
Pemaquid, ME · 2 mi
045416a
Chamberlain, ME · 2 mi
045686a
South Bristol, ME · 3 mi
045446a
East Boothbay, ME · 5 mi
045646a
Round Pond, ME · 5 mi
045386a
Boothbay Harbor, ME · 6 mi
045376a
Boothbay, ME · 6 mi
045736a
Walpole, ME · 6 mi

Maine planting zones →

Questions about 04554

What planting zone is ZIP code 04554?

ZIP code 04554 (New Harbor, ME) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in New Harbor, ME?

The median last spring frost (32 °F) near 04554 is April 28; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Westport Island station.

When is the first frost in New Harbor, ME?

The median first fall frost near 04554 is October 21, giving a median frost-free growing season of 175 days.

When should I plant tomatoes in 04554?

Start tomato seeds indoors around Mar 3 – Mar 17 and set transplants outside around May 5 – May 19, one to three weeks after the median last frost.

How much rain and snow does 04554 get?

About 50 inches of precipitation a year (NOAA 1991–2020 normals, Westport Island 2.2 Ssw station).

How hot do summers get in New Harbor, ME?

The average high peaks at 76 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 04554 have?

The USDA soil survey maps Sheepscot at the center of ZIP 04554: fine sandy loam, moderately well drained, pH about 5.1 (strongly acidic).

Did spring come early in New Harbor, ME in 2026?

Spring leaf-out near 04554 came on Apr 17 in 2026, 5 days earlier than the 1991–2020 average (Apr 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in New Harbor, ME?

Long-day onions: the longest day near 04554 is 15 h 28 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).