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

Planting zone for 08873 — Somerset, NJ

ZIP code 08873 (Somerset, Somerset County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 15 and the first fall frost October 26.

Where ZIP 08873 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 15

First frostOct 26

2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Somerset, 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 Somerset, NJ

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

Safe for tender plantsMay 1only 10% chance of frost after

First fall frostOctober 26median — 10% chance by Oct 11

Growing season193 daysfrost-free, median

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

From the NOAA station New Brunswick 3 Se, NJ — 6 miles away, elevation 112 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 08873

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 4 – Mar 18

SpinachSow outdoors · Mar 4 – Mar 25

Broccoli, cabbageStart indoors · Feb 4 – Feb 18

Broccoli, cabbageTransplant · Mar 25 – Apr 8

Onion setsPlant outdoors · Mar 18 – Apr 1

PotatoesPlant outdoors · Mar 25 – Apr 8

LettuceSow outdoors · Mar 18 – Apr 1

Carrots, beetsSow outdoors · Mar 25 – Apr 8

TomatoesStart indoors · Feb 18 – Mar 4

TomatoesTransplant · Apr 22 – May 6

Peppers, eggplantStart indoors · Feb 4 – Feb 18

Peppers, eggplantTransplant · Apr 29 – May 13

BeansSow outdoors · Apr 22 – May 6

Sweet cornSow outdoors · Apr 22 – May 6

Cucumbers, squashSow outdoors · Apr 22 – May 6

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 26) 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 08873 came on Mar 24 — about the same time as the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 24

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.

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 Somerset, NJ.

Soil in Somerset, NJ

The soil mapped at the center of ZIP 08873 is Royce — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Royce silt loam, 2 to 6 percent slopes.

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 08873; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Somerset, NJ

Summer high87 °Faverage high, July

Winter low23 °Faverage low, January

Hot days24days a year at 90 °F or more

Freezing nights111nights a year at 32 °F or less

Growing degree days3,486base 50 °F — the season’s usable heat

Longest day15 h 04 mindaylight on June 21

Shortest day9 h 16 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

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: New Brunswick 3 Se, NJ (6 mi away); precipitation: Franklin Twp 3.1 Ne, NJ (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

South Bound Brook, NJ · 4 mi

088357a

Manville, NJ · 4 mi

089067a

New Brunswick, NJ · 4 mi

089337a

New Brunswick, NJ · 4 mi

089027a

North Brunswick, NJ · 5 mi

088547a

Piscataway, NJ · 5 mi

All 2 ZIP codes in Somerset → · New Jersey planting zones →

Questions about 08873

What planting zone is ZIP code 08873?

ZIP code 08873 (Somerset, 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 Somerset, NJ?

The median last spring frost (32 °F) near 08873 is April 15; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, New Brunswick 3 Se station.

When is the first frost in Somerset, NJ?

The median first fall frost near 08873 is October 26, giving a median frost-free growing season of 193 days.

When should I plant tomatoes in 08873?

Start tomato seeds indoors around Feb 18 – Mar 4 and set transplants outside around Apr 22 – May 6, one to three weeks after the median last frost.

How much rain and snow does 08873 get?

About 49.5 inches of precipitation a year (NOAA 1991–2020 normals, Franklin Twp 3.1 Ne station).

How hot do summers get in Somerset, 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 08873 have?

The USDA soil survey maps Royce at the center of ZIP 08873: silt loam, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Somerset, NJ in 2026?

Spring leaf-out near 08873 came on Mar 24 in 2026, about the same as the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Somerset, NJ?

Long-day onions: the longest day near 08873 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 08873 change?

Yes. The 2012 USDA map put 08873 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.