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

Planting zone for 18917 — Dublin, PA

ZIP code 18917 (Dublin, Bucks County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 13 and the first fall frost October 30.

Where ZIP 18917 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 13

First frostOct 30

2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dublin, 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 Dublin, PA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsApril 27only 10% chance of frost after

First fall frostOctober 30median — 10% chance by Oct 15

Growing season198 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 10.

From the NOAA station Doylestown Airport, PA — 5 miles away, elevation 394 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 18917

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

Fall lettuce, spinachSow outdoors · Sep 4 – Sep 18

GarlicPlant cloves · Oct 16 – Nov 20

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Oct 30) 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 18917 came on Mar 26 — 5 days earlier than the 1991–2020 average (Mar 31).

average
Mar 312026
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 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.

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 Dublin, PA.

Soil in Dublin, PA

The soil mapped at the center of ZIP 18917 is Abbottstown — silt loam, somewhat poorly drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilt loama good balance for most vegetables

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2.5%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Abbottstown complex, 0 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 18917; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dublin, 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 17 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation49.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Doylestown Airport, PA (5 mi away); precipitation: Perkasie 1.6 Sse, PA (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

189237a

Fountainville, PA · 2 mi

189447a

Perkasie, PA · 2 mi

189117a

Blooming Glen, PA · 3 mi

189497a

Plumsteadville, PA · 3 mi

Bedminster, PA · 4 mi

189627a

Silverdale, PA · 4 mi

Pennsylvania planting zones →

Questions about 18917

What planting zone is ZIP code 18917?

ZIP code 18917 (Dublin, 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 Dublin, PA?

The median last spring frost (32 °F) near 18917 is April 13; after April 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Doylestown Airport station.

When is the first frost in Dublin, PA?

The median first fall frost near 18917 is October 30, giving a median frost-free growing season of 198 days.

When should I plant tomatoes in 18917?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 18917 get?

About 49.5 inches of precipitation a year (NOAA 1991–2020 normals, Perkasie 1.6 Sse station).

How hot do summers get in Dublin, PA?

The average high peaks at 86 °F in July, with about 20 days a year at 90 °F or more.

What kind of soil does 18917 have?

The USDA soil survey maps Abbottstown at the center of ZIP 18917: silt loam, somewhat poorly drained, pH about 5.5 (moderately acidic).

Did spring come early in Dublin, PA in 2026?

Spring leaf-out near 18917 came on Mar 26 in 2026, 5 days earlier than the 1991–2020 average (Mar 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dublin, PA?

Long-day onions: the longest day near 18917 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 18917 change?

Yes. The 2012 USDA map put 18917 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.