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

Planting zone for 08625 — Trenton, NJ

ZIP code 08625 (Trenton, Mercer County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 17 and the first fall frost October 28.

Where ZIP 08625 is

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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 17
First frostOct 28
2012 zone7a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Trenton, NJ…

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 Trenton, NJ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 17median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 28median — 10% chance by Oct 11
Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 7.

From the NOAA station Trenton State College, NJ — 4 miles away, elevation 102 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 08625

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 6 – Mar 20
SpinachSow outdoors · Mar 6 – Mar 27
Broccoli, cabbageStart indoors · Feb 6 – Feb 20
Broccoli, cabbageTransplant · Mar 27 – Apr 10
Onion setsPlant outdoors · Mar 20 – Apr 3
PotatoesPlant outdoors · Mar 27 – Apr 10
LettuceSow outdoors · Mar 20 – Apr 3
Carrots, beetsSow outdoors · Mar 27 – Apr 10
TomatoesStart indoors · Feb 20 – Mar 6
TomatoesTransplant · Apr 24 – May 8
Peppers, eggplantStart indoors · Feb 6 – Feb 20
Peppers, eggplantTransplant · May 1 – May 15
BeansSow outdoors · Apr 24 – May 8
Sweet cornSow outdoors · Apr 24 – May 8
Cucumbers, squashSow outdoors · Apr 24 – May 8
Fall lettuce, spinachSow outdoors · Sep 2 – Sep 16
GarlicPlant cloves · Oct 14 – Nov 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 17) and first fall frost (Oct 28) 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 08625 came on Mar 22 — about the same time as the 1991–2020 average (Mar 23).

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 7a in New Jersey

600 plants native to the lower 48 states, recorded in New Jersey, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 80

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 119

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °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 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 201

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 175

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 10

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium 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 Trenton, NJ.

Soil in Trenton, NJ

The soil mapped at the center of ZIP 08625 is Sassafras — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.75%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Sassafras sandy loam, 2 to 5 percent slopes, Northern Coastal Plain.

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 08625; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Trenton, NJ

Summer high87 °Faverage high, July
Winter low23 °Faverage low, January
Hot days24days a year at 90 °F or more
Freezing nights109nights a year at 32 °F or less
Growing degree days3,400base 50 °F — the season’s usable heat
Longest day15 h 03 mindaylight on June 21
Shortest day9 h 18 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation47.5 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 40 °F, low 23 °F 40°23° JanFebruary: average high 43 °F, low 24 °F 43°24° FebMarch: average high 51 °F, low 31 °F 51°31° MarApril: average high 63 °F, low 41 °F 63°41° AprMay: average high 73 °F, low 50 °F 73°50° MayJune: average high 82 °F, low 59 °F 82°59° JunJuly: average high 87 °F, low 65 °F 87°65° JulAugust: average high 84 °F, low 63 °F 84°63° AugSeptember: average high 78 °F, low 56 °F 78°56° SepOctober: average high 66 °F, low 44 °F 66°44° OctNovember: average high 55 °F, low 35 °F 55°35° NovDecember: average high 45 °F, low 26 °F 45°26° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.64 in precipitation 3.6 JanFebruary: 2.79 in precipitation 2.8 FebMarch: 4.09 in precipitation 4.1 MarApril: 3.59 in precipitation 3.6 AprMay: 4.10 in precipitation 4.1 MayJune: 4.51 in precipitation 4.5 JunJuly: 4.97 in precipitation 5.0 JulAugust: 4.30 in precipitation 4.3 AugSeptember: 4.13 in precipitation 4.1 SepOctober: 4.01 in precipitation 4.0 OctNovember: 3.26 in precipitation 3.3 NovDecember: 4.08 in precipitation 4.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Trenton State College, NJ (4 mi away); precipitation: Lawrence Twp 1.8 Ssw, NJ (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

085437a
Princeton, NJ · <1 mi
086017a
Trenton, NJ · <1 mi
086027a
Trenton, NJ · <1 mi
086037a
Trenton, NJ · <1 mi
086047a
Trenton, NJ · <1 mi
086057a
Trenton, NJ · <1 mi
086067a
Trenton, NJ · <1 mi
086077a
Trenton, NJ · <1 mi

All 25 ZIP codes in Trenton → · New Jersey planting zones →

Questions about 08625

What planting zone is ZIP code 08625?

ZIP code 08625 (Trenton, NJ) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Trenton, NJ?

The median last spring frost (32 °F) near 08625 is April 17; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Trenton State College station.

When is the first frost in Trenton, NJ?

The median first fall frost near 08625 is October 28, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 08625?

Start tomato seeds indoors around Feb 20 – Mar 6 and set transplants outside around Apr 24 – May 8, one to three weeks after the median last frost.

How much rain and snow does 08625 get?

About 47.5 inches of precipitation a year (NOAA 1991–2020 normals, Lawrence Twp 1.8 Ssw station).

How hot do summers get in Trenton, NJ?

The average high peaks at 87 °F in July, with about 24 days a year at 90 °F or more.

What kind of soil does 08625 have?

The USDA soil survey maps Sassafras at the center of ZIP 08625: sandy loam, well drained, pH about 6.3 (slightly acidic).

Did spring come early in Trenton, NJ in 2026?

Spring leaf-out near 08625 came on Mar 22 in 2026, about the same as the 1991–2020 average (Mar 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Trenton, NJ?

Long-day onions: the longest day near 08625 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).