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

Planting zone for 07938 — Liberty Corner, NJ

ZIP code 07938 (Liberty Corner, Somerset County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 30 and the first fall frost October 20.

Where ZIP 07938 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 30
First frostOct 20
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 Liberty Corner, 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 Liberty Corner, NJ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 5
Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 31.

From the NOAA station Somerville 4 Nw, NJ — 4 miles away, elevation 135 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 07938

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 20) 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 07938 came on Mar 26 — 5 days earlier than the 1991–2020 average (Mar 31).

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 Liberty Corner, NJ

The soil mapped at the center of ZIP 07938 is Parsippany — slightly decomposed plant material, poorly drained.

TextureSlightly decomposed plant materialtop layer
pH5.4strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter85%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Parsippany silt loam, 0 to 3 percent slopes, frequently flooded.

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 07938; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Liberty Corner, NJ

Summer high86 °Faverage high, July
Winter low19 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights137nights a year at 32 °F or less
Growing degree days2,964base 50 °F — the season’s usable heat
Longest day15 h 05 mindaylight on June 21
Shortest day9 h 15 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation48.3 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 39 °F, low 19 °F 39°19° JanFebruary: average high 41 °F, low 20 °F 41°20° FebMarch: average high 50 °F, low 27 °F 50°27° MarApril: average high 62 °F, low 36 °F 62°36° AprMay: average high 72 °F, low 46 °F 72°46° MayJune: average high 81 °F, low 56 °F 81°56° JunJuly: average high 86 °F, low 62 °F 86°62° JulAugust: average high 83 °F, low 60 °F 83°60° AugSeptember: average high 77 °F, low 53 °F 77°53° SepOctober: average high 64 °F, low 41 °F 64°41° OctNovember: average high 54 °F, low 31 °F 54°31° NovDecember: average high 43 °F, low 24 °F 43°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.50 in precipitation 3.5 JanFebruary: 2.70 in precipitation 2.7 FebMarch: 4.09 in precipitation 4.1 MarApril: 3.80 in precipitation 3.8 AprMay: 4.01 in precipitation 4.0 MayJune: 4.51 in precipitation 4.5 JunJuly: 4.92 in precipitation 4.9 JulAugust: 4.55 in precipitation 4.5 AugSeptember: 4.22 in precipitation 4.2 SepOctober: 4.27 in precipitation 4.3 OctNovember: 3.47 in precipitation 3.5 NovDecember: 4.28 in precipitation 4.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Somerville 4 Nw, NJ (4 mi away); precipitation: Bernards Twp 0.6 Nnw, NJ (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

079397a
Lyons, NJ · 2 mi
079317a
Far Hills, NJ · 2 mi
079207a
Basking Ridge, NJ · 3 mi
079787a
Pluckemin, NJ · 3 mi
070597a
Warren, NJ · 4 mi
088367a
Martinsville, NJ · 4 mi
079467a
Millington, NJ · 4 mi
088077a
Bridgewater, NJ · 5 mi

New Jersey planting zones →

Questions about 07938

What planting zone is ZIP code 07938?

ZIP code 07938 (Liberty Corner, 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 Liberty Corner, NJ?

The median last spring frost (32 °F) near 07938 is April 30; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Somerville 4 Nw station.

When is the first frost in Liberty Corner, NJ?

The median first fall frost near 07938 is October 20, giving a median frost-free growing season of 172 days.

When should I plant tomatoes in 07938?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 07938 get?

About 48.3 inches of precipitation a year (NOAA 1991–2020 normals, Bernards Twp 0.6 Nnw station).

How hot do summers get in Liberty Corner, NJ?

The average high peaks at 86 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 07938 have?

The USDA soil survey maps Parsippany at the center of ZIP 07938: slightly decomposed plant material, poorly drained, pH about 5.4 (strongly acidic).

Did spring come early in Liberty Corner, NJ in 2026?

Spring leaf-out near 07938 came on Mar 26 in 2026, 5 days earlier than the 1991–2020 average (Mar 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Liberty Corner, NJ?

Long-day onions: the longest day near 07938 is 15 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 07938 change?

Yes. The 2012 USDA map put 07938 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.