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

Planting zone for 03244 — Hillsborough, NH

ZIP code 03244 (Hillsborough, Hillsborough) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 9 and the first fall frost October 5.

Where ZIP 03244 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostMay 9
First frostOct 5
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hillsborough, 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 Hillsborough, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 9median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 5median — 10% chance by Sep 25
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 29 and returns around October 13.

From the NOAA station Weare 2 Ne, NH — 9 miles away, elevation 804 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 03244

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 28 – Apr 11
SpinachSow outdoors · Mar 28 – Apr 18
Broccoli, cabbageStart indoors · Feb 28 – Mar 14
Broccoli, cabbageTransplant · Apr 18 – May 2
Onion setsPlant outdoors · Apr 11 – Apr 25
PotatoesPlant outdoors · Apr 18 – May 2
LettuceSow outdoors · Apr 11 – Apr 25
Carrots, beetsSow outdoors · Apr 18 – May 2
TomatoesStart indoors · Mar 14 – Mar 28
TomatoesTransplant · May 16 – May 30
Peppers, eggplantStart indoors · Feb 28 – Mar 14
Peppers, eggplantTransplant · May 23 – Jun 6
BeansSow outdoors · May 16 – May 30
Sweet cornSow outdoors · May 16 – May 30
Cucumbers, squashSow outdoors · May 16 – May 30
Fall lettuce, spinachSow outdoors · Aug 10 – Aug 24
GarlicPlant cloves · Sep 21 – Oct 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 5) 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 03244 came on Apr 12 — 6 days earlier than the 1991–2020 average (Apr 18).

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 6a in New Hampshire

486 plants native to the lower 48 states, recorded in New Hampshire, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 99

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 171

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 142

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 7

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 creeper2 ft · blooms summer · high shade tolerance · to −13 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °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 Hillsborough, NH.

Soil in Hillsborough, NH

The soil mapped at the center of ZIP 03244 is Marlow — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH3.5strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter85%high
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of local importanceUSDA classification

Map unit: Marlow fine sandy loam, 0 to 8 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 03244; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hillsborough, NH

Summer high82 °Faverage high, July
Winter low12 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights172nights a year at 32 °F or less
Growing degree days2,507base 50 °F — the season’s usable heat
Longest day15 h 23 mindaylight on June 21
Shortest day8 h 59 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation47.4 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 12 °F 30°12° JanFebruary: average high 34 °F, low 13 °F 34°13° FebMarch: average high 42 °F, low 22 °F 42°22° MarApril: average high 56 °F, low 33 °F 56°33° AprMay: average high 68 °F, low 46 °F 68°46° MayJune: average high 77 °F, low 55 °F 77°55° JunJuly: average high 82 °F, low 60 °F 82°60° JulAugust: average high 81 °F, low 59 °F 81°59° AugSeptember: average high 73 °F, low 51 °F 73°51° SepOctober: average high 59 °F, low 38 °F 59°38° OctNovember: average high 46 °F, low 29 °F 46°29° NovDecember: average high 36 °F, low 20 °F 36°20° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.26 in precipitation 3.3 JanFebruary: 3.17 in precipitation 3.2 FebMarch: 3.78 in precipitation 3.8 MarApril: 3.67 in precipitation 3.7 AprMay: 3.61 in precipitation 3.6 MayJune: 4.50 in precipitation 4.5 JunJuly: 4.42 in precipitation 4.4 JulAugust: 4.07 in precipitation 4.1 AugSeptember: 3.74 in precipitation 3.7 SepOctober: 4.92 in precipitation 4.9 OctNovember: 3.88 in precipitation 3.9 NovDecember: 4.39 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Weare 2 Ne, NH (9 mi away); precipitation: Weare 2 Ne, NH (9 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.

034406a
Antrim, NH · 5 mi
032425b
Henniker, NH · 6 mi
034425b
Bennington, NH · 7 mi
032215b
Bradford, NH · 10 mi
034646a
Stoddard, NH · 10 mi
032806a
Washington, NH · 10 mi
030436a
Francestown, NH · 10 mi
034496a
Hancock, NH · 10 mi

New Hampshire planting zones →

Questions about 03244

What planting zone is ZIP code 03244?

ZIP code 03244 (Hillsborough, NH) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Hillsborough, NH?

The median last spring frost (32 °F) near 03244 is May 9; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Weare 2 Ne station.

When is the first frost in Hillsborough, NH?

The median first fall frost near 03244 is October 5, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 03244?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 03244 get?

About 47.4 inches of precipitation a year (NOAA 1991–2020 normals, Weare 2 Ne station).

How hot do summers get in Hillsborough, NH?

The average high peaks at 82 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 03244 have?

The USDA soil survey maps Marlow at the center of ZIP 03244: slightly decomposed plant material, well drained, pH about 3.5 (strongly acidic).

Did spring come early in Hillsborough, NH in 2026?

Spring leaf-out near 03244 came on Apr 12 in 2026, 6 days earlier than the 1991–2020 average (Apr 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hillsborough, NH?

Long-day onions: the longest day near 03244 is 15 h 23 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 03244 change?

Yes. The 2012 USDA map put 03244 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.