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

Planting zone for 15956 — South Fork, PA

ZIP code 15956 (South Fork, Cambria County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 29 and the first fall frost October 21.

Where ZIP 15956 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 29
First frostOct 21
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 South Fork, 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 South Fork, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 17only 10% chance of frost after
First fall frostOctober 21median — 10% chance by Oct 5
Growing season176 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 17 and returns around November 2.

From the NOAA station Johnstown Cambria Co. Airport, PA — 3 miles away, elevation 2,284 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 15956

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 26 – Sep 9
GarlicPlant cloves · Oct 7 – Nov 11
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 21) 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 15956 came on Mar 16 — 20 days earlier than the 1991–2020 average (Apr 5).

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 6a in Pennsylvania

598 plants native to the lower 48 states, recorded in Pennsylvania, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 76

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 121

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 207

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 170

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °F

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 South Fork, PA.

Soil in South Fork, PA

The soil mapped at the center of ZIP 15956 is Cookport — channery loam, moderately well drained.

TextureChannery loama good balance for most vegetables
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Cookport and Ernest very stony soils, 8 to 25 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 15956; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in South Fork, PA

Summer high79 °Faverage high, July
Winter low19 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights127nights a year at 32 °F or less
Growing degree days2,605base 50 °F — the season’s usable heat
Longest day15 h 03 mindaylight on June 21
Shortest day9 h 17 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation41.3 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 33 °F, low 19 °F 33°19° JanFebruary: average high 36 °F, low 21 °F 36°21° FebMarch: average high 45 °F, low 28 °F 45°28° MarApril: average high 58 °F, low 38 °F 58°38° AprMay: average high 68 °F, low 49 °F 68°49° MayJune: average high 75 °F, low 57 °F 75°57° JunJuly: average high 79 °F, low 61 °F 79°61° JulAugust: average high 77 °F, low 60 °F 77°60° AugSeptember: average high 71 °F, low 53 °F 71°53° SepOctober: average high 59 °F, low 43 °F 59°43° OctNovember: average high 47 °F, low 33 °F 47°33° NovDecember: average high 38 °F, low 25 °F 38°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.54 in precipitation 2.5 JanFebruary: 2.53 in precipitation 2.5 FebMarch: 3.12 in precipitation 3.1 MarApril: 3.54 in precipitation 3.5 AprMay: 4.12 in precipitation 4.1 MayJune: 4.40 in precipitation 4.4 JunJuly: 4.22 in precipitation 4.2 JulAugust: 3.95 in precipitation 4.0 AugSeptember: 3.99 in precipitation 4.0 SepOctober: 3.06 in precipitation 3.1 OctNovember: 3.11 in precipitation 3.1 NovDecember: 2.68 in precipitation 2.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Johnstown Cambria Co. Airport, PA (3 mi away); precipitation: Johnstown Cambria Co. Airport, PA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

159516a
Saint Michael, PA · 2 mi
159426a
Mineral Point, PA · 3 mi
159526a
Salix, PA · 3 mi
159046b
Johnstown, PA · 3 mi
159456b
Parkhill, PA · 4 mi
159586a
Summerhill, PA · 4 mi
159026b
Johnstown, PA · 4 mi
159626a
Wilmore, PA · 5 mi

Pennsylvania planting zones →

Questions about 15956

What planting zone is ZIP code 15956?

ZIP code 15956 (South Fork, 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 South Fork, PA?

The median last spring frost (32 °F) near 15956 is April 29; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Johnstown Cambria Co. Airport station.

When is the first frost in South Fork, PA?

The median first fall frost near 15956 is October 21, giving a median frost-free growing season of 176 days.

When should I plant tomatoes in 15956?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 15956 get?

About 41.3 inches of precipitation a year (NOAA 1991–2020 normals, Johnstown Cambria Co. Airport station).

How hot do summers get in South Fork, PA?

The average high peaks at 79 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 15956 have?

The USDA soil survey maps Cookport at the center of ZIP 15956: channery loam, moderately well drained, pH about 5.0 (strongly acidic).

Did spring come early in South Fork, PA in 2026?

Spring leaf-out near 15956 came on Mar 16 in 2026, 20 days earlier than the 1991–2020 average (Apr 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in South Fork, PA?

Long-day onions: the longest day near 15956 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).