Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 03440 — Antrim, NH

ZIP code 03440 (Antrim, 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 03440 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 Antrim, 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 Antrim, 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 — 11 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 03440

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 03440 came on Apr 12 — 6 days earlier than the 1991–2020 average (Apr 18).

average
Apr 182026
Apr 12

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).

Soil in Antrim, NH

The soil mapped at the center of ZIP 03440 is Becket — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH4.9strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter80%high

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of local importanceUSDA classification

Map unit: Becket 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 03440; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Antrim, 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 22 mindaylight on June 21

Shortest day9 h 00 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

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Weare 2 Ne, NH (11 mi away); precipitation: Weare 2 Ne, NH (11 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.

034425b

Bennington, NH · 5 mi

032446a

Hillsborough, NH · 5 mi

Harrisville, NH · 9 mi

030436a

Francestown, NH · 9 mi

030476a

Greenfield, NH · 10 mi

New Hampshire planting zones →

Questions about 03440

What planting zone is ZIP code 03440?

ZIP code 03440 (Antrim, 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 Antrim, NH?

The median last spring frost (32 °F) near 03440 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 Antrim, NH?

The median first fall frost near 03440 is October 5, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 03440?

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 03440 get?

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

How hot do summers get in Antrim, 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 03440 have?

The USDA soil survey maps Becket at the center of ZIP 03440: slightly decomposed plant material, well drained, pH about 4.9 (strongly acidic).

Did spring come early in Antrim, NH in 2026?

Spring leaf-out near 03440 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 Antrim, NH?

Long-day onions: the longest day near 03440 is 15 h 22 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 03440 change?

Yes. The 2012 USDA map put 03440 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.