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

Planting zone for 15085 — Trafford, PA

ZIP code 15085 (Trafford, Westmoreland County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 22 and the first fall frost October 25.

Where ZIP 15085 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 22

First frostOct 25

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 Trafford, 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 Trafford, PA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 22median — 50% chance of a later frost

Safe for tender plantsMay 12only 10% chance of frost after

First fall frostOctober 25median — 10% chance by Oct 10

Growing season186 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around November 5.

From the NOAA station Murrysville 2 Sw, PA — 2 miles away, elevation 860 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 15085

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 11 – Mar 25

SpinachSow outdoors · Mar 11 – Apr 1

Broccoli, cabbageStart indoors · Feb 11 – Feb 25

Broccoli, cabbageTransplant · Apr 1 – Apr 15

Onion setsPlant outdoors · Mar 25 – Apr 8

PotatoesPlant outdoors · Apr 1 – Apr 15

LettuceSow outdoors · Mar 25 – Apr 8

Carrots, beetsSow outdoors · Apr 1 – Apr 15

TomatoesStart indoors · Feb 25 – Mar 11

TomatoesTransplant · Apr 29 – May 13

Peppers, eggplantStart indoors · Feb 11 – Feb 25

Peppers, eggplantTransplant · May 6 – May 20

BeansSow outdoors · Apr 29 – May 13

Sweet cornSow outdoors · Apr 29 – May 13

Cucumbers, squashSow outdoors · Apr 29 – May 13

Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13

GarlicPlant cloves · Oct 11 – Nov 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 25) 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 15085 came on Mar 10 — 17 days earlier than the 1991–2020 average (Mar 27).

average
Mar 272026
Mar 10

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).

Soil in Trafford, PA

The soil mapped at the center of ZIP 15085 is Vandergrift — silty clay loam, moderately well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH6.0slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter3%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Vandergrift silt loam, 3 to 8 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 15085; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Trafford, PA

Summer high86 °Faverage high, July

Winter low22 °Faverage low, January

Hot days27days a year at 90 °F or more

Freezing nights129nights a year at 32 °F or less

Growing degree days3,342base 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)

Precipitation43.6 inper year, rain and melted snow

Snowfall25 inper year; 34 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

Monroeville, PA · 4 mi

151486b

Wilmerding, PA · 4 mi

156366b

Harrison City, PA · 4 mi

150356b

East Mc Keesport, PA · 4 mi

151376b

North Versailles, PA · 4 mi

Pennsylvania planting zones →

Questions about 15085

What planting zone is ZIP code 15085?

ZIP code 15085 (Trafford, 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 Trafford, PA?

The median last spring frost (32 °F) near 15085 is April 22; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Murrysville 2 Sw station.

When is the first frost in Trafford, PA?

The median first fall frost near 15085 is October 25, giving a median frost-free growing season of 186 days.

When should I plant tomatoes in 15085?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 15085 get?

About 43.6 inches of precipitation a year and 25 inches of snowfall (NOAA 1991–2020 normals, Murrysville 2 Sw station).

How hot do summers get in Trafford, PA?

The average high peaks at 86 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 15085 have?

The USDA soil survey maps Vandergrift at the center of ZIP 15085: silty clay loam, moderately well drained, pH about 6.0 (slightly acidic).

Did spring come early in Trafford, PA in 2026?

Spring leaf-out near 15085 came on Mar 10 in 2026, 17 days earlier than the 1991–2020 average (Mar 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Trafford, PA?

Long-day onions: the longest day near 15085 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 15085 change?

Yes. The 2012 USDA map put 15085 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.