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

Planting zone for 15003 — Ambridge, PA

ZIP code 15003 (Ambridge, Beaver County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 8 and the first fall frost November 8.

Where ZIP 15003 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 8
First frostNov 8
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 Ambridge, 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 Ambridge, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 8median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostNovember 8median — 10% chance by Oct 27
Growing season212 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 29 and returns around November 18.

From the NOAA station Glenwillard Dashields L&D, PA — 4 miles away, elevation 709 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 15003

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 25 – Mar 11
SpinachSow outdoors · Feb 25 – Mar 18
Broccoli, cabbageStart indoors · Jan 28 – Feb 11
Broccoli, cabbageTransplant · Mar 18 – Apr 1
Onion setsPlant outdoors · Mar 11 – Mar 25
PotatoesPlant outdoors · Mar 18 – Apr 1
LettuceSow outdoors · Mar 11 – Mar 25
Carrots, beetsSow outdoors · Mar 18 – Apr 1
TomatoesStart indoors · Feb 11 – Feb 25
TomatoesTransplant · Apr 15 – Apr 29
Peppers, eggplantStart indoors · Jan 28 – Feb 11
Peppers, eggplantTransplant · Apr 22 – May 6
BeansSow outdoors · Apr 15 – Apr 29
Sweet cornSow outdoors · Apr 15 – Apr 29
Cucumbers, squashSow outdoors · Apr 15 – Apr 29
Fall lettuce, spinachSow outdoors · Sep 13 – Sep 27
GarlicPlant cloves · Oct 25 – Nov 29
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 8) and first fall frost (Nov 8) 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 15003 came on Mar 10 — 17 days earlier than the 1991–2020 average (Mar 27).

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 Ambridge, PA.

Soil in Ambridge, PA

The soil mapped at the center of ZIP 15003 is Gilpin — channery silt loam, well drained.

TextureChannery silt loama good balance for most vegetables
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3.9%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Gilpin-Upshur complex, 15 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 15003; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ambridge, PA

Summer high84 °Faverage high, July
Winter low21 °Faverage low, January
Hot days26days a year at 90 °F or more
Freezing nights93nights a year at 32 °F or less
Growing degree days3,218base 50 °F — the season’s usable heat
Longest day15 h 05 mindaylight on June 21
Shortest day9 h 16 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation38.5 inper year, rain and melted snow
Snowfall20 inper year; 17 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 36 °F, low 21 °F 36°21° JanFebruary: average high 39 °F, low 22 °F 39°22° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 61 °F, low 40 °F 61°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 76 °F, low 56 °F 76°56° SepOctober: average high 64 °F, low 45 °F 64°45° OctNovember: average high 50 °F, low 34 °F 50°34° NovDecember: average high 40 °F, low 27 °F 40°27° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 2.59 in precipitation, 9.1 in snowfall 2.6❄9 JanFebruary: 2.68 in precipitation, 5.2 in snowfall 2.7❄5 FebMarch: 3.20 in precipitation, 2.6 in snowfall 3.2❄3 MarApril: 3.59 in precipitation 3.6 AprMay: 3.55 in precipitation 3.5 MayJune: 4.22 in precipitation 4.2 JunJuly: 3.86 in precipitation 3.9 JulAugust: 3.16 in precipitation 3.2 AugSeptember: 3.45 in precipitation 3.5 SepOctober: 2.78 in precipitation, 0.1 in snowfall 2.8 OctNovember: 2.68 in precipitation, 0.3 in snowfall 2.7 NovDecember: 2.79 in precipitation, 2.5 in snowfall 2.8❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Glenwillard Dashields L&D, PA (4 mi away); precipitation: Glenwillard Dashields L&D, PA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

150816b
South Heights, PA · 2 mi
150567a
Leetsdale, PA · 3 mi
150056b
Baden, PA · 3 mi
150467a
Crescent, PA · 3 mi
151436b
Sewickley, PA · 4 mi
150276b
Conway, PA · 5 mi
150016b
Aliquippa, PA · 6 mi
150426b
Freedom, PA · 6 mi

Pennsylvania planting zones →

Questions about 15003

What planting zone is ZIP code 15003?

ZIP code 15003 (Ambridge, 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 Ambridge, PA?

The median last spring frost (32 °F) near 15003 is April 8; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Glenwillard Dashields L&D station.

When is the first frost in Ambridge, PA?

The median first fall frost near 15003 is November 8, giving a median frost-free growing season of 212 days.

When should I plant tomatoes in 15003?

Start tomato seeds indoors around Feb 11 – Feb 25 and set transplants outside around Apr 15 – Apr 29, one to three weeks after the median last frost.

How much rain and snow does 15003 get?

About 38.5 inches of precipitation a year and 20 inches of snowfall (NOAA 1991–2020 normals, Glenwillard Dashields L&D station).

How hot do summers get in Ambridge, PA?

The average high peaks at 84 °F in July, with about 26 days a year at 90 °F or more.

What kind of soil does 15003 have?

The USDA soil survey maps Gilpin at the center of ZIP 15003: channery silt loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Ambridge, PA in 2026?

Spring leaf-out near 15003 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 Ambridge, PA?

Long-day onions: the longest day near 15003 is 15 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).