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

Planting zone for 04427 — Corinth, ME

ZIP code 04427 (Corinth, Penobscot County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 8 and the first fall frost October 3.

Where ZIP 04427 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostMay 8
First frostOct 3
2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Corinth, 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 Corinth, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 21
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 15.

From the NOAA station Corinna, ME — 12 miles away, elevation 299 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 04427

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22
GarlicPlant cloves · Sep 19 – Oct 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 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 04427 came on Apr 17 — 8 days earlier than the 1991–2020 average (Apr 25).

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 5a in Maine

483 plants native to the lower 48 states, recorded in Maine, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 53

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 96

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 166

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 151

alpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °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 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °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 Corinth, ME.

Soil in Corinth, ME

The soil mapped at the center of ZIP 04427 is Pushaw — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter6%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Pushaw-Boothbay complex, 3 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 04427; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Corinth, ME

Summer high81 °Faverage high, July
Winter low6 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights175nights a year at 32 °F or less
Growing degree days2,146base 50 °F — the season’s usable heat
Longest day15 h 37 mindaylight on June 21
Shortest day8 h 46 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation44.7 inper year, rain and melted snow
Snowfall72 inper year; 113 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 6 °F 28°6° JanFebruary: average high 32 °F, low 7 °F 32°7° FebMarch: average high 41 °F, low 18 °F 41°18° MarApril: average high 54 °F, low 31 °F 54°31° AprMay: average high 67 °F, low 43 °F 67°43° MayJune: average high 75 °F, low 52 °F 75°52° JunJuly: average high 81 °F, low 58 °F 81°58° JulAugust: average high 80 °F, low 56 °F 80°56° AugSeptember: average high 72 °F, low 48 °F 72°48° SepOctober: average high 59 °F, low 37 °F 59°37° OctNovember: average high 46 °F, low 27 °F 46°27° NovDecember: average high 34 °F, low 16 °F 34°16° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.36 in precipitation, 16.6 in snowfall 3.4❄17 JanFebruary: 2.82 in precipitation, 17.2 in snowfall 2.8❄17 FebMarch: 3.44 in precipitation, 13.4 in snowfall 3.4❄13 MarApril: 3.83 in precipitation, 3.4 in snowfall 3.8❄3 AprMay: 3.64 in precipitation 3.6 MayJune: 4.02 in precipitation 4.0 JunJuly: 3.22 in precipitation 3.2 JulAugust: 3.59 in precipitation 3.6 AugSeptember: 3.56 in precipitation 3.6 SepOctober: 4.77 in precipitation, 0.3 in snowfall 4.8 OctNovember: 4.11 in precipitation, 4.1 in snowfall 4.1❄4 NovDecember: 4.34 in precipitation, 16.5 in snowfall 4.3❄17 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Corinna, ME (12 mi away); precipitation: Corinna, ME (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5a.

044355a
Exeter, ME · 6 mi
044505a
Kenduskeag, ME · 6 mi
044495a
Hudson, ME · 6 mi
044225a
Charleston, ME · 7 mi
044565a
Levant, ME · 7 mi
044105a
Bradford, ME · 9 mi
044885a
Stetson, ME · 9 mi
049395a
Garland, ME · 10 mi

Maine planting zones →

Questions about 04427

What planting zone is ZIP code 04427?

ZIP code 04427 (Corinth, ME) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Corinth, ME?

The median last spring frost (32 °F) near 04427 is May 8; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Corinna station.

When is the first frost in Corinth, ME?

The median first fall frost near 04427 is October 3, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 04427?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 04427 get?

About 44.7 inches of precipitation a year and 72 inches of snowfall (NOAA 1991–2020 normals, Corinna station).

How hot do summers get in Corinth, ME?

The average high peaks at 81 °F in July, with about 5 days a year at 90 °F or more.

What kind of soil does 04427 have?

The USDA soil survey maps Pushaw at the center of ZIP 04427: silt loam, somewhat poorly drained, pH about 5.3 (strongly acidic).

Did spring come early in Corinth, ME in 2026?

Spring leaf-out near 04427 came on Apr 17 in 2026, 8 days earlier than the 1991–2020 average (Apr 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Corinth, ME?

Long-day onions: the longest day near 04427 is 15 h 37 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 04427 change?

Yes. The 2012 USDA map put 04427 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.