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

Planting zone for Warminster, PA

Warminster, PA is in USDA zone 7a across its 2 ZIP codes. The median last spring frost is April 11 and the first fall frost November 1.

Warminster on the zone map

Outlined: its 1 ZIP code areas · 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.

Zone7a0 to 5 °F
ZIP codes2
Last frostApr 11
First frostNov 1
Growing season205 days

7a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Warminster, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 11median — 50% chance of a later frost
Safe for tender plantsApril 27only 10% chance of frost after
First fall frostNovember 1median — 10% chance by Oct 17
Growing season205 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 13.

From the NOAA station Willow Grove NAS, PA, elevation 361 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 Warminster

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 28 – Mar 14
SpinachSow outdoors · Feb 28 – Mar 21
Broccoli, cabbageStart indoors · Jan 31 – Feb 14
Broccoli, cabbageTransplant · Mar 21 – Apr 4
Onion setsPlant outdoors · Mar 14 – Mar 28
PotatoesPlant outdoors · Mar 21 – Apr 4
LettuceSow outdoors · Mar 14 – Mar 28
Carrots, beetsSow outdoors · Mar 21 – Apr 4
TomatoesStart indoors · Feb 14 – Feb 28
TomatoesTransplant · Apr 18 – May 2
Peppers, eggplantStart indoors · Jan 31 – Feb 14
Peppers, eggplantTransplant · Apr 25 – May 9
BeansSow outdoors · Apr 18 – May 2
Sweet cornSow outdoors · Apr 18 – May 2
Cucumbers, squashSow outdoors · Apr 18 – May 2
Fall lettuce, spinachSow outdoors · Sep 6 – Sep 20
GarlicPlant cloves · Oct 18 – Nov 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 11) and first fall frost (Nov 1) 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 18991 came on Mar 24 — 4 days earlier than the 1991–2020 average (Mar 28).

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 7a in Pennsylvania

620 plants native to the lower 48 states, recorded in Pennsylvania, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 78

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 123

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 212

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 181

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 11

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °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 °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 Warminster, PA.

Soil in Warminster, PA

The soil mapped at the center of ZIP 18991 is Lansdale — loam, well drained.

TextureLoama good balance for most vegetables
pH5.4strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Lansdale 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 18991; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warminster, PA

Summer high86 °Faverage high, July
Winter low23 °Faverage low, January
Hot days20days a year at 90 °F or more
Freezing nights106nights a year at 32 °F or less
Growing degree days3,410base 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)
Precipitation47.7 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 39 °F, low 23 °F 39°23° JanFebruary: average high 42 °F, low 25 °F 42°25° FebMarch: average high 50 °F, low 31 °F 50°31° MarApril: average high 63 °F, low 41 °F 63°41° AprMay: average high 72 °F, low 51 °F 72°51° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 86 °F, low 65 °F 86°65° JulAugust: average high 84 °F, low 63 °F 84°63° AugSeptember: average high 77 °F, low 57 °F 77°57° SepOctober: average high 65 °F, low 45 °F 65°45° OctNovember: average high 54 °F, low 36 °F 54°36° NovDecember: average high 44 °F, low 28 °F 44°28° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.16 in precipitation 3.2 JanFebruary: 2.47 in precipitation 2.5 FebMarch: 3.88 in precipitation 3.9 MarApril: 3.91 in precipitation 3.9 AprMay: 4.27 in precipitation 4.3 MayJune: 4.24 in precipitation 4.2 JunJuly: 5.48 in precipitation 5.5 JulAugust: 4.86 in precipitation 4.9 AugSeptember: 4.35 in precipitation 4.3 SepOctober: 3.75 in precipitation 3.8 OctNovember: 3.35 in precipitation 3.4 NovDecember: 3.95 in precipitation 4.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Doylestown Airport, PA (within 1 mile); precipitation: Doylestown Airport, PA (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Warminster

189747a
0 to 5 °F
189917a
0 to 5 °F

Pennsylvania planting zones →

Questions about Warminster

What planting zone is Warminster, PA?

Warminster, PA is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Warminster, PA?

The median last spring frost is April 11 and the median first fall frost is November 1 (NOAA 1991–2020 normals, Willow Grove NAS station).

When can I plant a garden in Warminster, PA?

Cool-season crops like peas and spinach go in around Feb 28 – Mar 21; tomatoes, peppers, beans and squash after about Apr 18, once frost risk has passed.

What kind of onions grow in Warminster, PA?

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

How much rain and snow does Warminster, PA get?

About 47.7 inches of precipitation a year (NOAA 1991–2020 normals).