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

Planting zone for 03221 — Bradford, NH

ZIP code 03221 (Bradford, Merrimack County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 15 and the first fall frost September 27.

Where ZIP 03221 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 15

First frostSep 27

2012 zone5a

Was 5a 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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bradford, 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 Bradford, NH

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 15median — 50% chance of a later frost

Safe for tender plantsMay 29only 10% chance of frost after

First fall frostSeptember 27median — 10% chance by Sep 15

Growing season135 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 8.

From the NOAA station Bradford 2, NH — 2 miles away, elevation 814 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 03221

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 3 – Apr 17

SpinachSow outdoors · Apr 3 – Apr 24

Broccoli, cabbageStart indoors · Mar 6 – Mar 20

Broccoli, cabbageTransplant · Apr 24 – May 8

Onion setsPlant outdoors · Apr 17 – May 1

PotatoesPlant outdoors · Apr 24 – May 8

LettuceSow outdoors · Apr 17 – May 1

Carrots, beetsSow outdoors · Apr 24 – May 8

TomatoesStart indoors · Mar 20 – Apr 3

TomatoesTransplant · May 22 – Jun 5

Peppers, eggplantStart indoors · Mar 6 – Mar 20

Peppers, eggplantTransplant · May 29 – Jun 12

BeansSow outdoors · May 22 – Jun 5

Sweet cornSow outdoors · May 22 – Jun 5

Cucumbers, squashSow outdoors · May 22 – Jun 5

Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16

GarlicPlant cloves · Sep 13 – Oct 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 15) and first fall frost (Sep 27) 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 03221 came on Apr 15 — 4 days earlier than the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 15

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 Bradford, NH

The soil mapped at the center of ZIP 03221 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, 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 03221; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bradford, NH

Summer high80 °Faverage high, July

Winter low12 °Faverage low, January

Hot days3days a year at 90 °F or more

Freezing nights176nights a year at 32 °F or less

Growing degree days2,054base 50 °F — the season’s usable heat

Longest day15 h 24 mindaylight on June 21

Shortest day8 h 58 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation49.5 inper year, rain and melted snow

Snowfall68 inper year; 96 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bradford 2, NH (2 mi away); precipitation: Bradford 2, NH (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

032725b

South Newbury, NH · 3 mi

032735b

South Sutton, NH · 3 mi

North Sutton, NH · 8 mi

032806a

Washington, NH · 8 mi

032425b

Henniker, NH · 9 mi

New Hampshire planting zones →

Questions about 03221

What planting zone is ZIP code 03221?

ZIP code 03221 (Bradford, 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 Bradford, NH?

The median last spring frost (32 °F) near 03221 is May 15; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bradford 2 station.

When is the first frost in Bradford, NH?

The median first fall frost near 03221 is September 27, giving a median frost-free growing season of 135 days.

When should I plant tomatoes in 03221?

Start tomato seeds indoors around Mar 20 – Apr 3 and set transplants outside around May 22 – Jun 5, one to three weeks after the median last frost.

How much rain and snow does 03221 get?

About 49.5 inches of precipitation a year and 68 inches of snowfall (NOAA 1991–2020 normals, Bradford 2 station).

How hot do summers get in Bradford, NH?

The average high peaks at 80 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 03221 have?

The USDA soil survey maps Peru at the center of ZIP 03221: moderately decomposed plant material, moderately well drained, pH about 4.9 (strongly acidic).

Did spring come early in Bradford, NH in 2026?

Spring leaf-out near 03221 came on Apr 15 in 2026, 4 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bradford, NH?

Long-day onions: the longest day near 03221 is 15 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 03221 change?

Yes. The 2012 USDA map put 03221 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.