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

Planting zone for 18976 — Warrington, PA

ZIP code 18976 (Warrington, Bucks County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 11 and the first fall frost November 1.

Where ZIP 18976 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 11
First frostNov 1
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Warrington, 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 Warrington, 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 — 3 miles away, 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 18976

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 18976 came on Mar 24 — about the same time as 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 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 Warrington, PA.

Soil in Warrington, PA

The soil mapped at the center of ZIP 18976 is Chalfont — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Chalfont silt loam, 0 to 3 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 18976; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warrington, PA

Summer high85 °Faverage high, July
Winter low24 °Faverage low, January
Hot days22days a year at 90 °F or more
Freezing nights92nights a year at 32 °F or less
Growing degree days3,507base 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)
Precipitation50 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 40 °F, low 24 °F 40°24° JanFebruary: average high 43 °F, low 26 °F 43°26° FebMarch: average high 51 °F, low 32 °F 51°32° MarApril: average high 63 °F, low 42 °F 63°42° AprMay: average high 72 °F, low 52 °F 72°52° MayJune: average high 81 °F, low 61 °F 81°61° JunJuly: average high 85 °F, low 67 °F 85°67° JulAugust: average high 83 °F, low 65 °F 83°65° AugSeptember: average high 76 °F, low 58 °F 76°58° SepOctober: average high 64 °F, low 47 °F 64°47° OctNovember: average high 54 °F, low 37 °F 54°37° NovDecember: average high 44 °F, low 30 °F 44°30° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.72 in precipitation 3.7 JanFebruary: 2.99 in precipitation 3.0 FebMarch: 4.33 in precipitation 4.3 MarApril: 3.88 in precipitation 3.9 AprMay: 4.22 in precipitation 4.2 MayJune: 4.50 in precipitation 4.5 JunJuly: 5.23 in precipitation 5.2 JulAugust: 4.52 in precipitation 4.5 AugSeptember: 4.55 in precipitation 4.5 SepOctober: 4.19 in precipitation 4.2 OctNovember: 3.43 in precipitation 3.4 NovDecember: 4.44 in precipitation 4.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Willow Grove NAS, PA (3 mi away); precipitation: Furlong 0.7 Sw, PA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

189297a
Jamison, PA · 3 mi
189017a
Doylestown, PA · 4 mi
190447a
Horsham, PA · 4 mi
189747a
Warminster, PA · 4 mi
189147a
Chalfont, PA · 5 mi
189367a
Montgomeryville, PA · 5 mi
189257a
Furlong, PA · 5 mi
190407a
Hatboro, PA · 5 mi

Pennsylvania planting zones →

Questions about 18976

What planting zone is ZIP code 18976?

ZIP code 18976 (Warrington, PA) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Warrington, PA?

The median last spring frost (32 °F) near 18976 is April 11; after April 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Willow Grove NAS station.

When is the first frost in Warrington, PA?

The median first fall frost near 18976 is November 1, giving a median frost-free growing season of 205 days.

When should I plant tomatoes in 18976?

Start tomato seeds indoors around Feb 14 – Feb 28 and set transplants outside around Apr 18 – May 2, one to three weeks after the median last frost.

How much rain and snow does 18976 get?

About 50 inches of precipitation a year (NOAA 1991–2020 normals, Furlong 0.7 Sw station).

How hot do summers get in Warrington, PA?

The average high peaks at 85 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 18976 have?

The USDA soil survey maps Chalfont at the center of ZIP 18976: silt loam, somewhat poorly drained, pH about 6.2 (slightly acidic).

Did spring come early in Warrington, PA in 2026?

Spring leaf-out near 18976 came on Mar 24 in 2026, about the same as the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Warrington, PA?

Long-day onions: the longest day near 18976 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).