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

Planting zone for 03243 — Hill, NH

ZIP code 03243 (Hill, Merrimack County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 7 and the first fall frost October 3.

Where ZIP 03243 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 7
First frostOct 3
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 Hill, 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 Hill, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 20only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 24
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 27 and returns around October 13.

From the NOAA station Franklin Falls Dam, NH — 7 miles away, elevation 449 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 03243

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
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 7) 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 03243 came on Apr 16 — 4 days earlier than the 1991–2020 average (Apr 20).

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 Hill, NH.

Soil in Hill, NH

The soil mapped at the center of ZIP 03243 is Peru — moderately decomposed plant material, moderately well drained.

TextureModerately decomposed plant materialtop layer
pH4.9strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter80%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classFarmland of local importanceUSDA classification

Map unit: Peru fine sandy loam, 8 to 15 percent slopes, 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 03243; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hill, NH

Summer high82 °Faverage high, July
Winter low9 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights174nights a year at 32 °F or less
Growing degree days2,209base 50 °F — the season’s usable heat
Longest day15 h 26 mindaylight on June 21
Shortest day8 h 56 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation49.2 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 30 °F, low 9 °F 30°9° JanFebruary: average high 33 °F, low 10 °F 33°10° FebMarch: average high 42 °F, low 20 °F 42°20° MarApril: average high 56 °F, low 31 °F 56°31° AprMay: average high 68 °F, low 43 °F 68°43° MayJune: average high 76 °F, low 52 °F 76°52° JunJuly: average high 82 °F, low 58 °F 82°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 26 °F 46°26° NovDecember: average high 35 °F, low 17 °F 35°17° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.31 in precipitation 3.3 JanFebruary: 3.00 in precipitation 3.0 FebMarch: 3.48 in precipitation 3.5 MarApril: 3.98 in precipitation 4.0 AprMay: 4.04 in precipitation 4.0 MayJune: 4.42 in precipitation 4.4 JunJuly: 4.06 in precipitation 4.1 JulAugust: 4.15 in precipitation 4.2 AugSeptember: 4.55 in precipitation 4.5 SepOctober: 5.36 in precipitation 5.4 OctNovember: 4.27 in precipitation 4.3 NovDecember: 4.55 in precipitation 4.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Franklin Falls Dam, NH (7 mi away); precipitation: Danbury 2.2 Ese, NH (2 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.

032305a
Danbury, NH · 5 mi
032315b
East Andover, NH · 5 mi
032165b
Andover, NH · 5 mi
032355b
Franklin, NH · 7 mi
032225b
Bristol, NH · 8 mi
032695b
Sanbornton, NH · 8 mi
032565b
New Hampton, NH · 9 mi
032875b
Wilmot, NH · 10 mi

New Hampshire planting zones →

Questions about 03243

What planting zone is ZIP code 03243?

ZIP code 03243 (Hill, 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 Hill, NH?

The median last spring frost (32 °F) near 03243 is May 7; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Franklin Falls Dam station.

When is the first frost in Hill, NH?

The median first fall frost near 03243 is October 3, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 03243?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 03243 get?

About 49.2 inches of precipitation a year (NOAA 1991–2020 normals, Danbury 2.2 Ese station).

How hot do summers get in Hill, NH?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 03243 have?

The USDA soil survey maps Peru at the center of ZIP 03243: moderately decomposed plant material, moderately well drained, pH about 4.9 (strongly acidic).

Did spring come early in Hill, NH in 2026?

Spring leaf-out near 03243 came on Apr 16 in 2026, 4 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hill, NH?

Long-day onions: the longest day near 03243 is 15 h 26 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).