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

Planting zone for 16256 — Smicksburg, PA

ZIP code 16256 (Smicksburg, Indiana County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 10 and the first fall frost October 12.

Where ZIP 16256 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 frostMay 10
First frostOct 12
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 Smicksburg, 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 Smicksburg, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 10median — 50% chance of a later frost
Safe for tender plantsMay 28only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 30
Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 26.

From the NOAA station Putneyville 2 Se Dam, PA — 9 miles away, elevation 1,280 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 16256

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 29 – Apr 12
SpinachSow outdoors · Mar 29 – Apr 19
Broccoli, cabbageStart indoors · Mar 1 – Mar 15
Broccoli, cabbageTransplant · Apr 19 – May 3
Onion setsPlant outdoors · Apr 12 – Apr 26
PotatoesPlant outdoors · Apr 19 – May 3
LettuceSow outdoors · Apr 12 – Apr 26
Carrots, beetsSow outdoors · Apr 19 – May 3
TomatoesStart indoors · Mar 15 – Mar 29
TomatoesTransplant · May 17 – May 31
Peppers, eggplantStart indoors · Mar 1 – Mar 15
Peppers, eggplantTransplant · May 24 – Jun 7
BeansSow outdoors · May 17 – May 31
Sweet cornSow outdoors · May 17 – May 31
Cucumbers, squashSow outdoors · May 17 – May 31
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 10) and first fall frost (Oct 12) 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 16256 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 Smicksburg, PA.

Soil in Smicksburg, PA

The soil mapped at the center of ZIP 16256 is Atkins — slightly decomposed plant material, poorly drained.

TextureSlightly decomposed plant materialtop layer
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter69%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Atkins-Philo complex, 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 16256; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Smicksburg, PA

Summer high82 °Faverage high, July
Winter low17 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,597base 50 °F — the season’s usable heat
Longest day15 h 07 mindaylight on June 21
Shortest day9 h 14 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.9 inper year, rain and melted snow
Snowfall42 inper year; 50 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 17 °F 35°17° JanFebruary: average high 38 °F, low 18 °F 38°18° FebMarch: average high 47 °F, low 24 °F 47°24° MarApril: average high 61 °F, low 35 °F 61°35° AprMay: average high 71 °F, low 45 °F 71°45° MayJune: average high 78 °F, low 54 °F 78°54° JunJuly: average high 82 °F, low 58 °F 82°58° JulAugust: average high 81 °F, low 57 °F 81°57° AugSeptember: average high 74 °F, low 50 °F 74°50° SepOctober: average high 62 °F, low 39 °F 62°39° OctNovember: average high 50 °F, low 30 °F 50°30° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.28 in precipitation, 13.3 in snowfall 3.3❄13 JanFebruary: 2.44 in precipitation, 10.2 in snowfall 2.4❄10 FebMarch: 3.47 in precipitation, 7.5 in snowfall 3.5❄8 MarApril: 4.10 in precipitation, 0.6 in snowfall 4.1❄1 AprMay: 4.02 in precipitation 4.0 MayJune: 4.79 in precipitation 4.8 JunJuly: 4.97 in precipitation 5.0 JulAugust: 4.54 in precipitation 4.5 AugSeptember: 4.23 in precipitation 4.2 SepOctober: 3.22 in precipitation, 0.1 in snowfall 3.2 OctNovember: 3.40 in precipitation, 2.2 in snowfall 3.4❄2 NovDecember: 3.45 in precipitation, 8.3 in snowfall 3.5❄8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Putneyville 2 Se Dam, PA (9 mi away); precipitation: Sagamore, PA (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

157636a
Northpoint, PA · 4 mi
162466a
Plumville, PA · 5 mi
157446a
Hamilton, PA · 5 mi
162116a
Beyer, PA · 6 mi
157476a
Home, PA · 6 mi
162226a
Dayton, PA · 7 mi
157806a
Valier, PA · 7 mi
162506a
Sagamore, PA · 8 mi

Pennsylvania planting zones →

Questions about 16256

What planting zone is ZIP code 16256?

ZIP code 16256 (Smicksburg, 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 Smicksburg, PA?

The median last spring frost (32 °F) near 16256 is May 10; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Putneyville 2 Se Dam station.

When is the first frost in Smicksburg, PA?

The median first fall frost near 16256 is October 12, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 16256?

Start tomato seeds indoors around Mar 15 – Mar 29 and set transplants outside around May 17 – May 31, one to three weeks after the median last frost.

How much rain and snow does 16256 get?

About 45.9 inches of precipitation a year and 42 inches of snowfall (NOAA 1991–2020 normals, Sagamore station).

How hot do summers get in Smicksburg, PA?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 16256 have?

The USDA soil survey maps Atkins at the center of ZIP 16256: slightly decomposed plant material, poorly drained, pH about 5.0 (strongly acidic).

Did spring come early in Smicksburg, PA in 2026?

Spring leaf-out near 16256 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 Smicksburg, PA?

Long-day onions: the longest day near 16256 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).