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

Planting zone for 03103 — Manchester, NH

ZIP code 03103 (Manchester, Hillsborough) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 21 and the first fall frost October 19.

Where ZIP 03103 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 frostApr 21
First frostOct 19
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 Manchester, 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 Manchester, NH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 21median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 4
Growing season180 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around November 1.

From the NOAA station Manchester Airport, NH — 2 miles away, elevation 226 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 03103

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 10 – Mar 24
SpinachSow outdoors · Mar 10 – Mar 31
Broccoli, cabbageStart indoors · Feb 10 – Feb 24
Broccoli, cabbageTransplant · Mar 31 – Apr 14
Onion setsPlant outdoors · Mar 24 – Apr 7
PotatoesPlant outdoors · Mar 31 – Apr 14
LettuceSow outdoors · Mar 24 – Apr 7
Carrots, beetsSow outdoors · Mar 31 – Apr 14
TomatoesStart indoors · Feb 24 – Mar 10
TomatoesTransplant · Apr 28 – May 12
Peppers, eggplantStart indoors · Feb 10 – Feb 24
Peppers, eggplantTransplant · May 5 – May 19
BeansSow outdoors · Apr 28 – May 12
Sweet cornSow outdoors · Apr 28 – May 12
Cucumbers, squashSow outdoors · Apr 28 – May 12
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 21) and first fall frost (Oct 19) 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 03103 came on Apr 11 — about the same time as the 1991–2020 average (Apr 13).

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 Manchester, NH.

Soil in Manchester, NH

The soil mapped at the center of ZIP 03103 is Windsor — loamy sand, excessively drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter3%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land.

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 03103; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Manchester, NH

Summer high84 °Faverage high, July
Winter low17 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights129nights a year at 32 °F or less
Growing degree days2,943base 50 °F — the season’s usable heat
Longest day15 h 21 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)
Precipitation40.4 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 34 °F, low 17 °F 34°17° JanFebruary: average high 37 °F, low 19 °F 37°19° FebMarch: average high 46 °F, low 27 °F 46°27° MarApril: average high 59 °F, low 38 °F 59°38° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 79 °F, low 58 °F 79°58° JunJuly: average high 84 °F, low 64 °F 84°64° JulAugust: average high 82 °F, low 62 °F 82°62° AugSeptember: average high 75 °F, low 54 °F 75°54° SepOctober: average high 62 °F, low 42 °F 62°42° OctNovember: average high 50 °F, low 33 °F 50°33° NovDecember: average high 39 °F, low 24 °F 39°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.44 in precipitation 2.4 JanFebruary: 2.73 in precipitation 2.7 FebMarch: 3.45 in precipitation 3.5 MarApril: 3.33 in precipitation 3.3 AprMay: 3.38 in precipitation 3.4 MayJune: 4.04 in precipitation 4.0 JunJuly: 3.30 in precipitation 3.3 JulAugust: 3.35 in precipitation 3.4 AugSeptember: 3.72 in precipitation 3.7 SepOctober: 3.88 in precipitation 3.9 OctNovember: 3.48 in precipitation 3.5 NovDecember: 3.29 in precipitation 3.3 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

031096a
Manchester, NH · 2 mi
031016a
Manchester, NH · 3 mi
031056a
Manchester, NH · 3 mi
031086a
Manchester, NH · 3 mi
031116a
Manchester, NH · 3 mi
031046a
Manchester, NH · 4 mi
031026a
Manchester, NH · 5 mi
030326a
Auburn, NH · 5 mi

All 8 ZIP codes in Manchester → · New Hampshire planting zones →

Questions about 03103

What planting zone is ZIP code 03103?

ZIP code 03103 (Manchester, 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 Manchester, NH?

The median last spring frost (32 °F) near 03103 is April 21; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Manchester Airport station.

When is the first frost in Manchester, NH?

The median first fall frost near 03103 is October 19, giving a median frost-free growing season of 180 days.

When should I plant tomatoes in 03103?

Start tomato seeds indoors around Feb 24 – Mar 10 and set transplants outside around Apr 28 – May 12, one to three weeks after the median last frost.

How much rain and snow does 03103 get?

About 40.4 inches of precipitation a year (NOAA 1991–2020 normals, Manchester Airport station).

How hot do summers get in Manchester, NH?

The average high peaks at 84 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 03103 have?

The USDA soil survey maps Windsor at the center of ZIP 03103: loamy sand, excessively drained, pH about 5.3 (strongly acidic).

Did spring come early in Manchester, NH in 2026?

Spring leaf-out near 03103 came on Apr 11 in 2026, about the same as the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Manchester, NH?

Long-day onions: the longest day near 03103 is 15 h 21 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 03103 change?

Yes. The 2012 USDA map put 03103 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.