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

Planting zone for 03782 — Sunapee, NH

ZIP code 03782 (Sunapee, Sullivan County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 2 and the first fall frost October 9.

Where ZIP 03782 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 2
First frostOct 9
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 Sunapee, NH…

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 Sunapee, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 2median — 50% chance of a later frost
Safe for tender plantsMay 17only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 27
Growing season158 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 21 and returns around October 21.

From the NOAA station Mt Sunapee, NH — 4 miles away, elevation 1,276 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 03782

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 21 – Apr 4
SpinachSow outdoors · Mar 21 – Apr 11
Broccoli, cabbageStart indoors · Feb 21 – Mar 7
Broccoli, cabbageTransplant · Apr 11 – Apr 25
Onion setsPlant outdoors · Apr 4 – Apr 18
PotatoesPlant outdoors · Apr 11 – Apr 25
LettuceSow outdoors · Apr 4 – Apr 18
Carrots, beetsSow outdoors · Apr 11 – Apr 25
TomatoesStart indoors · Mar 7 – Mar 21
TomatoesTransplant · May 9 – May 23
Peppers, eggplantStart indoors · Feb 21 – Mar 7
Peppers, eggplantTransplant · May 16 – May 30
BeansSow outdoors · May 9 – May 23
Sweet cornSow outdoors · May 9 – May 23
Cucumbers, squashSow outdoors · May 9 – May 23
Fall lettuce, spinachSow outdoors · Aug 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 9) 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 03782 came on Apr 15 — 6 days earlier than the 1991–2020 average (Apr 21).

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 New Hampshire

475 plants native to the lower 48 states, recorded in New Hampshire, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 167

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °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 °F

Grasses 141

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 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °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 Sunapee, NH.

Soil in Sunapee, NH

The soil mapped at the center of ZIP 03782 is Monadnock — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH4.8strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter85%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Monadnock-Lyman-Rock outcrop complex, 8 to 15 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 03782; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sunapee, NH

Summer high79 °Faverage high, July
Winter low13 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,177base 50 °F — the season’s usable heat
Longest day15 h 25 mindaylight on June 21
Shortest day8 h 57 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation47.7 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 29 °F, low 13 °F 29°13° JanFebruary: average high 32 °F, low 15 °F 32°15° FebMarch: average high 40 °F, low 22 °F 40°22° MarApril: average high 53 °F, low 33 °F 53°33° AprMay: average high 66 °F, low 44 °F 66°44° MayJune: average high 75 °F, low 54 °F 75°54° JunJuly: average high 79 °F, low 59 °F 79°59° JulAugust: average high 77 °F, low 57 °F 77°57° AugSeptember: average high 70 °F, low 50 °F 70°50° SepOctober: average high 57 °F, low 39 °F 57°39° OctNovember: average high 45 °F, low 29 °F 45°29° NovDecember: average high 34 °F, low 20 °F 34°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.14 in precipitation 3.1 JanFebruary: 3.04 in precipitation 3.0 FebMarch: 3.40 in precipitation 3.4 MarApril: 3.95 in precipitation 4.0 AprMay: 3.77 in precipitation 3.8 MayJune: 4.22 in precipitation 4.2 JunJuly: 4.16 in precipitation 4.2 JulAugust: 3.92 in precipitation 3.9 AugSeptember: 4.06 in precipitation 4.1 SepOctober: 5.58 in precipitation 5.6 OctNovember: 3.83 in precipitation 3.8 NovDecember: 4.63 in precipitation 4.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mt Sunapee, NH (4 mi away); precipitation: Newbury 1.6 Nw, NH (4 mi away). 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.

037545a
Guild, NH · 2 mi
037515b
Georges Mills, NH · 4 mi
032575b
New London, NH · 5 mi
037735a
Newport, NH · 6 mi
032555b
Newbury, NH · 6 mi
032845b
Springfield, NH · 7 mi
032725b
South Newbury, NH · 8 mi
037526a
Goshen, NH · 8 mi

New Hampshire planting zones →

Questions about 03782

What planting zone is ZIP code 03782?

ZIP code 03782 (Sunapee, NH) 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 Sunapee, NH?

The median last spring frost (32 °F) near 03782 is May 2; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mt Sunapee station.

When is the first frost in Sunapee, NH?

The median first fall frost near 03782 is October 9, giving a median frost-free growing season of 158 days.

When should I plant tomatoes in 03782?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 03782 get?

About 47.7 inches of precipitation a year (NOAA 1991–2020 normals, Newbury 1.6 Nw station).

How hot do summers get in Sunapee, NH?

The average high peaks at 79 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 03782 have?

The USDA soil survey maps Monadnock at the center of ZIP 03782: moderately decomposed plant material, well drained, pH about 4.8 (strongly acidic).

Did spring come early in Sunapee, NH in 2026?

Spring leaf-out near 03782 came on Apr 15 in 2026, 6 days earlier than the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sunapee, NH?

Long-day onions: the longest day near 03782 is 15 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).