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

Planting zone for 07839 — Greendell, NJ

ZIP code 07839 (Greendell, Sussex County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 25 and the first fall frost October 19.

Where ZIP 07839 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 25
First frostOct 19
2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Greendell, 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 Greendell, NJ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 5
Growing season175 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 31.

From the NOAA station Andover Aeroflex Airport, NJ — 5 miles away, elevation 584 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 07839

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
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 25) 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 07839 came on Apr 1 — 5 days earlier than the 1991–2020 average (Apr 6).

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 Greendell, NJ

The soil mapped at the center of ZIP 07839 is Alden — slightly decomposed plant material, very poorly drained.

TextureSlightly decomposed plant materialtop layer
DrainageVery poorly drainedconsider raised beds
Organic matter85%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Alden mucky silt loam, gneiss till substratum, 0 to 8 percent slopes, extremely stony.

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 07839; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Greendell, NJ

Summer high84 °Faverage high, July
Winter low19 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights127nights a year at 32 °F or less
Growing degree days2,877base 50 °F — the season’s usable heat
Longest day15 h 07 mindaylight on June 21
Shortest day9 h 13 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation50.3 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 36 °F, low 19 °F 36°19° JanFebruary: average high 39 °F, low 20 °F 39°20° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 61 °F, low 38 °F 61°38° AprMay: average high 71 °F, low 48 °F 71°48° MayJune: average high 79 °F, low 57 °F 79°57° JunJuly: average high 84 °F, low 62 °F 84°62° JulAugust: average high 82 °F, low 60 °F 82°60° AugSeptember: average high 74 °F, low 52 °F 74°52° SepOctober: average high 63 °F, low 42 °F 63°42° OctNovember: average high 52 °F, low 32 °F 52°32° NovDecember: average high 41 °F, low 25 °F 41°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.59 in precipitation 3.6 JanFebruary: 2.81 in precipitation 2.8 FebMarch: 4.15 in precipitation 4.2 MarApril: 3.86 in precipitation 3.9 AprMay: 4.01 in precipitation 4.0 MayJune: 4.84 in precipitation 4.8 JunJuly: 4.69 in precipitation 4.7 JulAugust: 4.96 in precipitation 5.0 AugSeptember: 4.63 in precipitation 4.6 SepOctober: 4.81 in precipitation 4.8 OctNovember: 3.53 in precipitation 3.5 NovDecember: 4.38 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Andover Aeroflex Airport, NJ (5 mi away); precipitation: Andover Twp 1.7 W, NJ (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

078796b
Tranquility, NJ · 2 mi
078466b
Johnsonburg, NJ · 3 mi
078206b
Allamuchy, NJ · 3 mi
078216b
Andover, NJ · 4 mi
078756b
Stillwater, NJ · 6 mi
078606b
Newton, NJ · 6 mi
078556b
Middleville, NJ · 6 mi
078746b
Stanhope, NJ · 7 mi

New Jersey planting zones →

Questions about 07839

What planting zone is ZIP code 07839?

ZIP code 07839 (Greendell, NJ) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Greendell, NJ?

The median last spring frost (32 °F) near 07839 is April 25; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Andover Aeroflex Airport station.

When is the first frost in Greendell, NJ?

The median first fall frost near 07839 is October 19, giving a median frost-free growing season of 175 days.

When should I plant tomatoes in 07839?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 07839 get?

About 50.3 inches of precipitation a year (NOAA 1991–2020 normals, Andover Twp 1.7 W station).

How hot do summers get in Greendell, NJ?

The average high peaks at 84 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 07839 have?

The USDA soil survey maps Alden at the center of ZIP 07839: slightly decomposed plant material, very poorly drained.

Did spring come early in Greendell, NJ in 2026?

Spring leaf-out near 07839 came on Apr 1 in 2026, 5 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Greendell, NJ?

Long-day onions: the longest day near 07839 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 07839 change?

Yes. The 2012 USDA map put 07839 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.