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

Planting zone for 03906 — North Berwick, ME

ZIP code 03906 (North Berwick, York County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 16 and the first fall frost September 30.

Where ZIP 03906 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostMay 16
First frostSep 30
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for North Berwick, 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 North Berwick, ME

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 16median — 50% chance of a later frost
Safe for tender plantsMay 29only 10% chance of frost after
First fall frostSeptember 30median — 10% chance by Sep 18
Growing season136 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 7.

From the NOAA station Sanford 2 Nnw, ME — 7 miles away, elevation 289 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 03906

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 4 – Apr 18
SpinachSow outdoors · Apr 4 – Apr 25
Broccoli, cabbageStart indoors · Mar 7 – Mar 21
Broccoli, cabbageTransplant · Apr 25 – May 9
Onion setsPlant outdoors · Apr 18 – May 2
PotatoesPlant outdoors · Apr 25 – May 9
LettuceSow outdoors · Apr 18 – May 2
Carrots, beetsSow outdoors · Apr 25 – May 9
TomatoesStart indoors · Mar 21 – Apr 4
TomatoesTransplant · May 23 – Jun 6
Peppers, eggplantStart indoors · Mar 7 – Mar 21
Peppers, eggplantTransplant · May 30 – Jun 13
BeansSow outdoors · May 23 – Jun 6
Sweet cornSow outdoors · May 23 – Jun 6
Cucumbers, squashSow outdoors · May 23 – Jun 6
Fall lettuce, spinachSow outdoors · Aug 5 – Aug 19
GarlicPlant cloves · Sep 16 – Oct 21
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 30) 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 03906 came on Apr 15 — about the same time as the 1991–2020 average (Apr 17).

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 5b in Maine

493 plants native to the lower 48 states, recorded in Maine, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 98

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 169

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 153

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 North Berwick, ME.

Soil in North Berwick, ME

The soil mapped at the center of ZIP 03906 is Peru — fine sandy loam, moderately well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter7%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classprime farmlandUSDA classification

Map unit: Peru fine sandy loam, 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 03906; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in North Berwick, ME

Summer high81 °Faverage high, July
Winter low10 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights156nights a year at 32 °F or less
Growing degree days2,120base 50 °F — the season’s usable heat
Longest day15 h 24 mindaylight on June 21
Shortest day8 h 58 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation51.3 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 32 °F, low 10 °F 32°10° JanFebruary: average high 35 °F, low 11 °F 35°11° FebMarch: average high 44 °F, low 20 °F 44°20° MarApril: average high 57 °F, low 30 °F 57°30° AprMay: average high 68 °F, low 41 °F 68°41° MayJune: average high 76 °F, low 51 °F 76°51° JunJuly: average high 81 °F, low 56 °F 81°56° JulAugust: average high 80 °F, low 55 °F 80°55° AugSeptember: average high 73 °F, low 47 °F 73°47° SepOctober: average high 61 °F, low 36 °F 61°36° OctNovember: average high 48 °F, low 27 °F 48°27° NovDecember: average high 37 °F, low 17 °F 37°17° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.68 in precipitation 3.7 JanFebruary: 3.62 in precipitation 3.6 FebMarch: 4.70 in precipitation 4.7 MarApril: 4.60 in precipitation 4.6 AprMay: 3.83 in precipitation 3.8 MayJune: 4.56 in precipitation 4.6 JunJuly: 3.96 in precipitation 4.0 JulAugust: 3.94 in precipitation 3.9 AugSeptember: 3.82 in precipitation 3.8 SepOctober: 5.35 in precipitation 5.3 OctNovember: 4.46 in precipitation 4.5 NovDecember: 4.79 in precipitation 4.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sanford 2 Nnw, ME (7 mi away); precipitation: Sanford 2 Nnw, ME (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

040735b
Sanford, ME · 5 mi
039016a
Berwick, ME · 5 mi
040906a
Wells, ME · 7 mi
040275b
Lebanon, ME · 7 mi
040835b
Springvale, ME · 8 mi
038686a
Rochester, NH · 8 mi
039086a
South Berwick, ME · 9 mi
038786a
Somersworth, NH · 9 mi

Maine planting zones →

Questions about 03906

What planting zone is ZIP code 03906?

ZIP code 03906 (North Berwick, ME) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in North Berwick, ME?

The median last spring frost (32 °F) near 03906 is May 16; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sanford 2 Nnw station.

When is the first frost in North Berwick, ME?

The median first fall frost near 03906 is September 30, giving a median frost-free growing season of 136 days.

When should I plant tomatoes in 03906?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 03906 get?

About 51.3 inches of precipitation a year (NOAA 1991–2020 normals, Sanford 2 Nnw station).

How hot do summers get in North Berwick, ME?

The average high peaks at 81 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 03906 have?

The USDA soil survey maps Peru at the center of ZIP 03906: fine sandy loam, moderately well drained, pH about 5.0 (strongly acidic).

Did spring come early in North Berwick, ME in 2026?

Spring leaf-out near 03906 came on Apr 15 in 2026, about the same as the 1991–2020 average (Apr 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in North Berwick, ME?

Long-day onions: the longest day near 03906 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).