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

Planting zone for 03261 — Northwood, NH

ZIP code 03261 (Northwood, Rockingham County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 8 and the first fall frost October 3.

Where ZIP 03261 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 8
First frostOct 3
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 Northwood, 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 Northwood, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostOctober 3median — 10% chance by Sep 21
Growing season146 daysfrost-free, median

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

From the NOAA station Concord Municipal Airport, NH — 14 miles away, elevation 348 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 03261

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
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 8) 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 03261 came on Apr 15 — about the same time as the 1991–2020 average (Apr 16).

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 Northwood, NH

The soil mapped at the center of ZIP 03261 is Chatfield — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
DrainageWell drainednatural drainage class
Organic matter95%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Chatfield-Hollis-Canton complex, 8 to 15 percent slopes, rocky.

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 03261; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Northwood, NH

Summer high83 °Faverage high, July
Winter low13 °Faverage low, January
Hot days14days a year at 90 °F or more
Freezing nights165nights a year at 32 °F or less
Growing degree days2,472base 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)
Precipitation46.3 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 32 °F, low 13 °F 32°13° JanFebruary: average high 35 °F, low 15 °F 35°15° FebMarch: average high 44 °F, low 23 °F 44°23° MarApril: average high 58 °F, low 33 °F 58°33° AprMay: average high 69 °F, low 44 °F 69°44° MayJune: average high 78 °F, low 54 °F 78°54° JunJuly: average high 83 °F, low 59 °F 83°59° JulAugust: average high 82 °F, low 57 °F 82°57° AugSeptember: average high 74 °F, low 49 °F 74°49° SepOctober: average high 61 °F, low 38 °F 61°38° OctNovember: average high 48 °F, low 29 °F 48°29° NovDecember: average high 37 °F, low 20 °F 37°20° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.03 in precipitation 3.0 JanFebruary: 2.89 in precipitation 2.9 FebMarch: 4.11 in precipitation 4.1 MarApril: 3.94 in precipitation 3.9 AprMay: 3.78 in precipitation 3.8 MayJune: 4.14 in precipitation 4.1 JunJuly: 3.85 in precipitation 3.9 JulAugust: 3.66 in precipitation 3.7 AugSeptember: 3.72 in precipitation 3.7 SepOctober: 5.15 in precipitation 5.2 OctNovember: 3.81 in precipitation 3.8 NovDecember: 4.23 in precipitation 4.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Concord Municipal Airport, NH (14 mi away); precipitation: Northwood 2.9 Wsw, NH (2 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.

032916a
West Nottingham, NH · 5 mi
038846a
Strafford, NH · 5 mi
030376a
Deerfield, NH · 5 mi
032345b
Epsom, NH · 6 mi
038156a
Center Strafford, NH · 7 mi
032635b
Pittsfield, NH · 7 mi
032906a
Nottingham, NH · 7 mi
032185b
Barnstead, NH · 9 mi

New Hampshire planting zones →

Questions about 03261

What planting zone is ZIP code 03261?

ZIP code 03261 (Northwood, 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 Northwood, NH?

The median last spring frost (32 °F) near 03261 is May 8; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Concord Municipal Airport station.

When is the first frost in Northwood, NH?

The median first fall frost near 03261 is October 3, giving a median frost-free growing season of 146 days.

When should I plant tomatoes in 03261?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 03261 get?

About 46.3 inches of precipitation a year (NOAA 1991–2020 normals, Northwood 2.9 Wsw station).

How hot do summers get in Northwood, NH?

The average high peaks at 83 °F in July, with about 14 days a year at 90 °F or more.

What kind of soil does 03261 have?

The USDA soil survey maps Chatfield at the center of ZIP 03261: slightly decomposed plant material, well drained.

Did spring come early in Northwood, NH in 2026?

Spring leaf-out near 03261 came on Apr 15 in 2026, about the same as the 1991–2020 average (Apr 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Northwood, NH?

Long-day onions: the longest day near 03261 is 15 h 23 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 03261 change?

Yes. The 2012 USDA map put 03261 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.