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

Planting zone for 18958 — Salfordville, PA

ZIP code 18958 (Salfordville, Montgomery County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 24 and the first fall frost October 15.

Where ZIP 18958 is

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 24

First frostOct 15

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 Salfordville, 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 Salfordville, PA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 24median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 15median — 10% chance by Oct 1

Growing season173 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around October 27.

From the NOAA station Graterford 1 E, PA — 4 miles away, elevation 279 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 18958

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 13 – Mar 27

SpinachSow outdoors · Mar 13 – Apr 3

Broccoli, cabbageStart indoors · Feb 13 – Feb 27

Broccoli, cabbageTransplant · Apr 3 – Apr 17

Onion setsPlant outdoors · Mar 27 – Apr 10

PotatoesPlant outdoors · Apr 3 – Apr 17

LettuceSow outdoors · Mar 27 – Apr 10

Carrots, beetsSow outdoors · Apr 3 – Apr 17

TomatoesStart indoors · Feb 27 – Mar 13

TomatoesTransplant · May 1 – May 15

Peppers, eggplantStart indoors · Feb 13 – Feb 27

Peppers, eggplantTransplant · May 8 – May 22

BeansSow outdoors · May 1 – May 15

Sweet cornSow outdoors · May 1 – May 15

Cucumbers, squashSow outdoors · May 1 – May 15

Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 15) 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 18958 came on Mar 24 — about the same time as the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 24

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 Salfordville, PA.

Soil in Salfordville, PA

The soil mapped at the center of ZIP 18958 is Readington — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH6.1slightly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Readington 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 18958; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Salfordville, PA

Summer high86 °Faverage high, July

Winter low20 °Faverage low, January

Hot days21days a year at 90 °F or more

Freezing nights137nights a year at 32 °F or less

Growing degree days3,234base 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)

Precipitation49.2 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: Graterford 1 E, PA (4 mi away); precipitation: Harleysville 3.9 Wnw, PA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

Spring Mount, PA · 2 mi

194417a

Harleysville, PA · 3 mi

194387a

Harleysville, PA · 3 mi

194927a

Zieglerville, PA · 3 mi

194737a

Schwenksville, PA · 3 mi

189187a

Earlington, PA · 4 mi

Pennsylvania planting zones →

Questions about 18958

What planting zone is ZIP code 18958?

ZIP code 18958 (Salfordville, 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 Salfordville, PA?

The median last spring frost (32 °F) near 18958 is April 24; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Graterford 1 E station.

When is the first frost in Salfordville, PA?

The median first fall frost near 18958 is October 15, giving a median frost-free growing season of 173 days.

When should I plant tomatoes in 18958?

Start tomato seeds indoors around Feb 27 – Mar 13 and set transplants outside around May 1 – May 15, one to three weeks after the median last frost.

How much rain and snow does 18958 get?

About 49.2 inches of precipitation a year (NOAA 1991–2020 normals, Harleysville 3.9 Wnw station).

How hot do summers get in Salfordville, PA?

The average high peaks at 86 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 18958 have?

The USDA soil survey maps Readington at the center of ZIP 18958: silt loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in Salfordville, PA in 2026?

Spring leaf-out near 18958 came on Mar 24 in 2026, about the same as the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Salfordville, PA?

Long-day onions: the longest day near 18958 is 15 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 18958 change?

Yes. The 2012 USDA map put 18958 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.