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

Planting zone for 17702 — Williamsport, PA

ZIP code 17702 (Williamsport, Lycoming 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 24.

Where ZIP 17702 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 25

First frostOct 24

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 Williamsport, 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 Williamsport, PA

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 12only 10% chance of frost after

First fall frostOctober 24median — 10% chance by Oct 8

Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 4.

From the NOAA station Williamsport 2, PA — 7 miles away, elevation 525 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 17702

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 29 – Sep 12

GarlicPlant cloves · Oct 10 – Nov 14

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 24) 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 17702 came on Apr 3 — 9 days earlier than the 1991–2020 average (Apr 12).

average
Apr 122026
Apr 3

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 6b in Pennsylvania

605 plants native to the lower 48 states, recorded in Pennsylvania, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Williamsport, PA.

Soil in Williamsport, PA

The soil mapped at the center of ZIP 17702 is Buchanan — slightly decomposed plant material, moderately well drained.

TextureSlightly decomposed plant materialtop layer

pH4.3strongly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter69%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Buchanan channery loam, 8 to 25 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 17702; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Williamsport, PA

Summer high86 °Faverage high, July

Winter low21 °Faverage low, January

Hot days25days a year at 90 °F or more

Freezing nights118nights a year at 32 °F or less

Growing degree days3,226base 50 °F — the season’s usable heat

Longest day15 h 09 mindaylight on June 21

Shortest day9 h 12 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation43.6 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: Williamsport 2, PA (7 mi away); precipitation: Williamsport 2.0 Ne, PA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

177446b

Linden, PA · 6 mi

177036b

Williamsport, PA · 6 mi

178106b

Allenwood, PA · 6 mi

177206b

Antes Fort, PA · 7 mi

177526b

Montgomery, PA · 8 mi

177406a

Jersey Shore, PA · 10 mi

178566b

New Columbia, PA · 10 mi

177286a

Cogan Station, PA · 10 mi

All 4 ZIP codes in Williamsport → · Pennsylvania planting zones →

Questions about 17702

What planting zone is ZIP code 17702?

ZIP code 17702 (Williamsport, PA) 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 Williamsport, PA?

The median last spring frost (32 °F) near 17702 is April 25; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Williamsport 2 station.

When is the first frost in Williamsport, PA?

The median first fall frost near 17702 is October 24, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 17702?

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 17702 get?

About 43.6 inches of precipitation a year (NOAA 1991–2020 normals, Williamsport 2.0 Ne station).

How hot do summers get in Williamsport, PA?

The average high peaks at 86 °F in July, with about 25 days a year at 90 °F or more.

What kind of soil does 17702 have?

The USDA soil survey maps Buchanan at the center of ZIP 17702: slightly decomposed plant material, moderately well drained, pH about 4.3 (strongly acidic).

Did spring come early in Williamsport, PA in 2026?

Spring leaf-out near 17702 came on Apr 3 in 2026, 9 days earlier than the 1991–2020 average (Apr 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Williamsport, PA?

Long-day onions: the longest day near 17702 is 15 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 17702 change?

Yes. The 2012 USDA map put 17702 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.