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

Planting zone for 15148 — Wilmerding, PA

ZIP code 15148 (Wilmerding, Allegheny County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 5 and the first fall frost November 10.

Where ZIP 15148 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 5
First frostNov 10
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 Wilmerding, 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 Wilmerding, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 5median — 50% chance of a later frost
Safe for tender plantsApril 22only 10% chance of frost after
First fall frostNovember 10median — 10% chance by Oct 28
Growing season219 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 27 and returns around November 23.

From the NOAA station Braddock Lock 2, PA — 3 miles away, elevation 732 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 15148

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 22 – Mar 8
SpinachSow outdoors · Feb 22 – Mar 15
Broccoli, cabbageStart indoors · Jan 25 – Feb 8
Broccoli, cabbageTransplant · Mar 15 – Mar 29
Onion setsPlant outdoors · Mar 8 – Mar 22
PotatoesPlant outdoors · Mar 15 – Mar 29
LettuceSow outdoors · Mar 8 – Mar 22
Carrots, beetsSow outdoors · Mar 15 – Mar 29
TomatoesStart indoors · Feb 8 – Feb 22
TomatoesTransplant · Apr 12 – Apr 26
Peppers, eggplantStart indoors · Jan 25 – Feb 8
Peppers, eggplantTransplant · Apr 19 – May 3
BeansSow outdoors · Apr 12 – Apr 26
Sweet cornSow outdoors · Apr 12 – Apr 26
Cucumbers, squashSow outdoors · Apr 12 – Apr 26
Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29
GarlicPlant cloves · Oct 27 – Dec 1
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 5) and first fall frost (Nov 10) 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 15148 came on Mar 10 — 16 days earlier than the 1991–2020 average (Mar 26).

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 Wilmerding, PA.

Soil in Wilmerding, PA

The soil mapped at the center of ZIP 15148 is Gilpin — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH4.3strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter69%high
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Gilpin-Upshur complex, very steep.

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 15148; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Wilmerding, PA

Summer high84 °Faverage high, July
Winter low22 °Faverage low, January
Hot days14days a year at 90 °F or more
Freezing nights92nights a year at 32 °F or less
Growing degree days3,275base 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)
Precipitation40.6 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 38 °F, low 22 °F 38°22° JanFebruary: average high 40 °F, low 22 °F 40°22° FebMarch: average high 50 °F, low 29 °F 50°29° MarApril: average high 62 °F, low 40 °F 62°40° AprMay: average high 72 °F, low 51 °F 72°51° MayJune: average high 80 °F, low 60 °F 80°60° JunJuly: average high 84 °F, low 64 °F 84°64° JulAugust: average high 83 °F, low 63 °F 83°63° AugSeptember: average high 77 °F, low 56 °F 77°56° SepOctober: average high 65 °F, low 44 °F 65°44° OctNovember: average high 53 °F, low 35 °F 53°35° NovDecember: average high 42 °F, low 28 °F 42°28° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.20 in precipitation 3.2 JanFebruary: 2.66 in precipitation 2.7 FebMarch: 3.29 in precipitation 3.3 MarApril: 3.19 in precipitation 3.2 AprMay: 3.86 in precipitation 3.9 MayJune: 4.72 in precipitation 4.7 JunJuly: 3.79 in precipitation 3.8 JulAugust: 3.74 in precipitation 3.7 AugSeptember: 3.32 in precipitation 3.3 SepOctober: 2.94 in precipitation 2.9 OctNovember: 2.88 in precipitation 2.9 NovDecember: 3.01 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Braddock Lock 2, PA (3 mi away); precipitation: Braddock Lock 2, PA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

150356b
East Mc Keesport, PA · <1 mi
151406b
Pitcairn, PA · 1 mi
151376b
North Versailles, PA · 1 mi
151456b
Turtle Creek, PA · 2 mi
151126b
East Pittsburgh, PA · 2 mi
151466b
Monroeville, PA · 3 mi
151106b
Duquesne, PA · 3 mi
151046b
Braddock, PA · 4 mi

Pennsylvania planting zones →

Questions about 15148

What planting zone is ZIP code 15148?

ZIP code 15148 (Wilmerding, 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 Wilmerding, PA?

The median last spring frost (32 °F) near 15148 is April 5; after April 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Braddock Lock 2 station.

When is the first frost in Wilmerding, PA?

The median first fall frost near 15148 is November 10, giving a median frost-free growing season of 219 days.

When should I plant tomatoes in 15148?

Start tomato seeds indoors around Feb 8 – Feb 22 and set transplants outside around Apr 12 – Apr 26, one to three weeks after the median last frost.

How much rain and snow does 15148 get?

About 40.6 inches of precipitation a year (NOAA 1991–2020 normals, Braddock Lock 2 station).

How hot do summers get in Wilmerding, PA?

The average high peaks at 84 °F in July, with about 14 days a year at 90 °F or more.

What kind of soil does 15148 have?

The USDA soil survey maps Gilpin at the center of ZIP 15148: slightly decomposed plant material, well drained, pH about 4.3 (strongly acidic).

Did spring come early in Wilmerding, PA in 2026?

Spring leaf-out near 15148 came on Mar 10 in 2026, 16 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Wilmerding, PA?

Long-day onions: the longest day near 15148 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).