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

Planting zone for 18657 — Tunkhannock, PA

ZIP code 18657 (Tunkhannock, Wyoming County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 23 and the first fall frost October 20.

Where ZIP 18657 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 23
First frostOct 20
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Tunkhannock, PA…

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 Tunkhannock, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 23median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 4
Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 3.

From the NOAA station Wilkes-Barre Intl Airport, PA — 18 miles away, elevation 932 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 18657

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 12 – Mar 26
SpinachSow outdoors · Mar 12 – Apr 2
Broccoli, cabbageStart indoors · Feb 12 – Feb 26
Broccoli, cabbageTransplant · Apr 2 – Apr 16
Onion setsPlant outdoors · Mar 26 – Apr 9
PotatoesPlant outdoors · Apr 2 – Apr 16
LettuceSow outdoors · Mar 26 – Apr 9
Carrots, beetsSow outdoors · Apr 2 – Apr 16
TomatoesStart indoors · Feb 26 – Mar 12
TomatoesTransplant · Apr 30 – May 14
Peppers, eggplantStart indoors · Feb 12 – Feb 26
Peppers, eggplantTransplant · May 7 – May 21
BeansSow outdoors · Apr 30 – May 14
Sweet cornSow outdoors · Apr 30 – May 14
Cucumbers, squashSow outdoors · Apr 30 – May 14
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 23) 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 18657 came on Apr 3 — 5 days earlier than the 1991–2020 average (Apr 8).

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 Tunkhannock, PA

The soil mapped at the center of ZIP 18657 is Lordstown — flaggy silt loam, well drained.

TextureFlaggy silt loama good balance for most vegetables
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter5%high
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Lordstown flaggy silt loam, 3 to 8 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 18657; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tunkhannock, PA

Summer high85 °Faverage high, July
Winter low20 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights122nights a year at 32 °F or less
Growing degree days3,103base 50 °F — the season’s usable heat
Longest day15 h 11 mindaylight on June 21
Shortest day9 h 10 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.4 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 36 °F, low 20 °F 36°20° JanFebruary: average high 39 °F, low 22 °F 39°22° FebMarch: average high 48 °F, low 29 °F 48°29° MarApril: average high 61 °F, low 39 °F 61°39° AprMay: average high 72 °F, low 50 °F 72°50° MayJune: average high 80 °F, low 58 °F 80°58° JunJuly: average high 85 °F, low 63 °F 85°63° JulAugust: average high 82 °F, low 61 °F 82°61° AugSeptember: average high 75 °F, low 54 °F 75°54° SepOctober: average high 63 °F, low 43 °F 63°43° OctNovember: average high 51 °F, low 34 °F 51°34° NovDecember: average high 40 °F, low 26 °F 40°26° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.14 in precipitation 3.1 JanFebruary: 2.36 in precipitation 2.4 FebMarch: 3.35 in precipitation 3.4 MarApril: 3.98 in precipitation 4.0 AprMay: 3.87 in precipitation 3.9 MayJune: 4.38 in precipitation 4.4 JunJuly: 4.23 in precipitation 4.2 JulAugust: 4.48 in precipitation 4.5 AugSeptember: 4.72 in precipitation 4.7 SepOctober: 4.24 in precipitation 4.2 OctNovember: 3.20 in precipitation 3.2 NovDecember: 3.42 in precipitation 3.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Wilkes-Barre Intl Airport, PA (18 mi away); precipitation: Forty Fort 0.4 Nne, PA (16 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

186256a
Lake Winola, PA · 6 mi
186156b
Falls, PA · 7 mi
184196a
Factoryville, PA · 9 mi
186296a
Mehoopany, PA · 9 mi
186306a
Meshoppen, PA · 10 mi
184406a
La Plume, PA · 10 mi
186366a
Noxen, PA · 11 mi
186186a
Harveys Lake, PA · 11 mi

Pennsylvania planting zones →

Questions about 18657

What planting zone is ZIP code 18657?

ZIP code 18657 (Tunkhannock, PA) 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 Tunkhannock, PA?

The median last spring frost (32 °F) near 18657 is April 23; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wilkes-Barre Intl Airport station.

When is the first frost in Tunkhannock, PA?

The median first fall frost near 18657 is October 20, giving a median frost-free growing season of 178 days.

When should I plant tomatoes in 18657?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 18657 get?

About 45.4 inches of precipitation a year (NOAA 1991–2020 normals, Forty Fort 0.4 Nne station).

How hot do summers get in Tunkhannock, PA?

The average high peaks at 85 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 18657 have?

The USDA soil survey maps Lordstown at the center of ZIP 18657: flaggy silt loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Tunkhannock, PA in 2026?

Spring leaf-out near 18657 came on Apr 3 in 2026, 5 days earlier than the 1991–2020 average (Apr 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Tunkhannock, PA?

Long-day onions: the longest day near 18657 is 15 h 11 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).