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

Planting zone for 15025 — Clairton, PA

ZIP code 15025 (Clairton, Allegheny County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 18 and the first fall frost October 28.

Where ZIP 15025 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 18
First frostOct 28
2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Clairton, 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 Clairton, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 28median — 10% chance by Oct 14
Growing season193 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 8.

From the NOAA station Pittsburgh Allegheny Co. Airport, PA — 4 miles away, elevation 1,247 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 15025

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Sep 2 – Sep 16
GarlicPlant cloves · Oct 14 – Nov 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 28) 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 15025 came on Mar 10 — 15 days earlier than the 1991–2020 average (Mar 25).

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.

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 122

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 209

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 173

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °F

Vines 10

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 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °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 Clairton, PA.

Soil in Clairton, PA

The center of ZIP 15025 is mapped as Urban land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 15025; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Clairton, PA

Summer high83 °Faverage high, July
Winter low22 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights106nights a year at 32 °F or less
Growing degree days3,286base 50 °F — the season’s usable heat
Longest day15 h 03 mindaylight on June 21
Shortest day9 h 18 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 37 °F, low 22 °F 37°22° JanFebruary: average high 40 °F, low 24 °F 40°24° FebMarch: average high 49 °F, low 31 °F 49°31° MarApril: average high 63 °F, low 42 °F 63°42° AprMay: average high 72 °F, low 52 °F 72°52° MayJune: average high 79 °F, low 60 °F 79°60° JunJuly: average high 83 °F, low 64 °F 83°64° JulAugust: average high 81 °F, low 63 °F 81°63° AugSeptember: average high 75 °F, low 56 °F 75°56° SepOctober: average high 63 °F, low 45 °F 63°45° OctNovember: average high 51 °F, low 35 °F 51°35° NovDecember: average high 41 °F, low 28 °F 41°28° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.08 in precipitation 3.1 JanFebruary: 2.57 in precipitation 2.6 FebMarch: 3.22 in precipitation 3.2 MarApril: 3.40 in precipitation 3.4 AprMay: 4.08 in precipitation 4.1 MayJune: 4.58 in precipitation 4.6 JunJuly: 3.93 in precipitation 3.9 JulAugust: 3.81 in precipitation 3.8 AugSeptember: 3.54 in precipitation 3.5 SepOctober: 3.06 in precipitation 3.1 OctNovember: 3.03 in precipitation 3.0 NovDecember: 3.04 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Pittsburgh Allegheny Co. Airport, PA (4 mi away); precipitation: Pittsburgh Allegheny Co. Airport, PA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

150886b
West Elizabeth, PA · 2 mi
150456b
Glassport, PA · 3 mi
150386b
Elrama, PA · 3 mi
151336b
Mckeesport, PA · 4 mi
151236b
West Mifflin, PA · 4 mi
151296b
South Park, PA · 4 mi
150346b
Dravosburg, PA · 4 mi
150376b
Elizabeth, PA · 5 mi

Pennsylvania planting zones →

Questions about 15025

What planting zone is ZIP code 15025?

ZIP code 15025 (Clairton, 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 Clairton, PA?

The median last spring frost (32 °F) near 15025 is April 18; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Pittsburgh Allegheny Co. Airport station.

When is the first frost in Clairton, PA?

The median first fall frost near 15025 is October 28, giving a median frost-free growing season of 193 days.

When should I plant tomatoes in 15025?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 15025 get?

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

How hot do summers get in Clairton, PA?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

Did spring come early in Clairton, PA in 2026?

Spring leaf-out near 15025 came on Mar 10 in 2026, 15 days earlier than the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Clairton, PA?

Long-day onions: the longest day near 15025 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).