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

Planting zone for 03846 — Jackson, NH

ZIP code 03846 (Jackson, Carroll County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 18 and the first fall frost October 1.

Where ZIP 03846 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 18
First frostOct 1
2012 zone5a

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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Jackson, 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 Jackson, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 18median — 50% chance of a later frost
Safe for tender plantsJune 1only 10% chance of frost after
First fall frostOctober 1median — 10% chance by Sep 15
Growing season135 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 4 and returns around October 12.

From the NOAA station Pinkham Notch, NH — 7 miles away, elevation 2,024 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 03846

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 6 – Apr 20
SpinachSow outdoors · Apr 6 – Apr 27
Broccoli, cabbageStart indoors · Mar 9 – Mar 23
Broccoli, cabbageTransplant · Apr 27 – May 11
Onion setsPlant outdoors · Apr 20 – May 4
PotatoesPlant outdoors · Apr 27 – May 11
LettuceSow outdoors · Apr 20 – May 4
Carrots, beetsSow outdoors · Apr 27 – May 11
TomatoesStart indoors · Mar 23 – Apr 6
TomatoesTransplant · May 25 – Jun 8
Peppers, eggplantStart indoors · Mar 9 – Mar 23
Peppers, eggplantTransplant · Jun 1 – Jun 15
BeansSow outdoors · May 25 – Jun 8
Sweet cornSow outdoors · May 25 – Jun 8
Cucumbers, squashSow outdoors · May 25 – Jun 8
Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20
GarlicPlant cloves · Sep 17 – Oct 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 18) and first fall frost (Oct 1) 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 03846 came on Apr 23 — 10 days earlier than the 1991–2020 average (May 3).

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 New Hampshire

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

Trees 52

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 93

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 165

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 140

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 Jackson, NH.

Soil in Jackson, NH

The soil mapped at the center of ZIP 03846 is Marlow — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH4.8strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter4%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Marlow fine sandy loam association, steep, very stony.

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 03846; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Jackson, NH

Summer high75 °Faverage high, July
Winter low6 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights185nights a year at 32 °F or less
Growing degree days1,475base 50 °F — the season’s usable heat
Longest day15 h 31 mindaylight on June 21
Shortest day8 h 52 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation56 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 26 °F, low 6 °F 26°6° JanFebruary: average high 28 °F, low 7 °F 28°7° FebMarch: average high 36 °F, low 15 °F 36°15° MarApril: average high 49 °F, low 27 °F 49°27° AprMay: average high 62 °F, low 39 °F 62°39° MayJune: average high 70 °F, low 48 °F 70°48° JunJuly: average high 75 °F, low 53 °F 75°53° JulAugust: average high 74 °F, low 52 °F 74°52° AugSeptember: average high 68 °F, low 45 °F 68°45° SepOctober: average high 54 °F, low 35 °F 54°35° OctNovember: average high 42 °F, low 24 °F 42°24° NovDecember: average high 32 °F, low 14 °F 32°14° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 4.12 in precipitation 4.1 JanFebruary: 3.34 in precipitation 3.3 FebMarch: 3.92 in precipitation 3.9 MarApril: 4.63 in precipitation 4.6 AprMay: 5.10 in precipitation 5.1 MayJune: 5.57 in precipitation 5.6 JunJuly: 4.71 in precipitation 4.7 JulAugust: 4.92 in precipitation 4.9 AugSeptember: 4.22 in precipitation 4.2 SepOctober: 5.86 in precipitation 5.9 OctNovember: 4.68 in precipitation 4.7 NovDecember: 4.94 in precipitation 4.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Pinkham Notch, NH (7 mi away); precipitation: Jackson 3.7 Nw, NH (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

038385a
Glen, NH · 6 mi
038135a
Center Conway, NH · 6 mi
038455a
Intervale, NH · 6 mi
038475b
Kearsarge, NH · 8 mi
038125a
Bartlett, NH · 10 mi
038605a
North Conway, NH · 10 mi
035935a
Randolph, NH · 11 mi
040375a
Fryeburg, ME · 12 mi

New Hampshire planting zones →

Questions about 03846

What planting zone is ZIP code 03846?

ZIP code 03846 (Jackson, NH) 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 Jackson, NH?

The median last spring frost (32 °F) near 03846 is May 18; after June 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Pinkham Notch station.

When is the first frost in Jackson, NH?

The median first fall frost near 03846 is October 1, giving a median frost-free growing season of 135 days.

When should I plant tomatoes in 03846?

Start tomato seeds indoors around Mar 23 – Apr 6 and set transplants outside around May 25 – Jun 8, one to three weeks after the median last frost.

How much rain and snow does 03846 get?

About 56 inches of precipitation a year (NOAA 1991–2020 normals, Jackson 3.7 Nw station).

How hot do summers get in Jackson, NH?

The average high peaks at 75 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 03846 have?

The USDA soil survey maps Marlow at the center of ZIP 03846: fine sandy loam, well drained, pH about 4.8 (strongly acidic).

Did spring come early in Jackson, NH in 2026?

Spring leaf-out near 03846 came on Apr 23 in 2026, 10 days earlier than the 1991–2020 average (May 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Jackson, NH?

Long-day onions: the longest day near 03846 is 15 h 31 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).