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

Planting zone for 15348 — Millsboro, PA

ZIP code 15348 (Millsboro, Washington County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 3 and the first fall frost October 15.

Where ZIP 15348 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 frostMay 3
First frostOct 15
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 Millsboro, 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 Millsboro, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 3median — 50% chance of a later frost
Safe for tender plantsMay 21only 10% chance of frost after
First fall frostOctober 15median — 10% chance by Oct 2
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 25.

From the NOAA station Waynesburg 1 E, PA — 11 miles away, elevation 942 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 15348

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 22 – Apr 5
SpinachSow outdoors · Mar 22 – Apr 12
Broccoli, cabbageStart indoors · Feb 22 – Mar 8
Broccoli, cabbageTransplant · Apr 12 – Apr 26
Onion setsPlant outdoors · Apr 5 – Apr 19
PotatoesPlant outdoors · Apr 12 – Apr 26
LettuceSow outdoors · Apr 5 – Apr 19
Carrots, beetsSow outdoors · Apr 12 – Apr 26
TomatoesStart indoors · Mar 8 – Mar 22
TomatoesTransplant · May 10 – May 24
Peppers, eggplantStart indoors · Feb 22 – Mar 8
Peppers, eggplantTransplant · May 17 – May 31
BeansSow outdoors · May 10 – May 24
Sweet cornSow outdoors · May 10 – May 24
Cucumbers, squashSow outdoors · May 10 – May 24
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 (May 3) 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 15348 came on Mar 10 — 15 days earlier than 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 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 Millsboro, PA.

Soil in Millsboro, PA

The center of ZIP 15348 is mapped as Urban land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 15348; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Millsboro, PA

Summer high83 °Faverage high, July
Winter low19 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights138nights a year at 32 °F or less
Growing degree days2,943base 50 °F — the season’s usable heat
Longest day15 h 01 mindaylight on June 21
Shortest day9 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation43.1 inper year, rain and melted snow
Snowfall30 inper year; 30 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 39 °F, low 19 °F 39°19° JanFebruary: average high 42 °F, low 21 °F 42°21° FebMarch: average high 51 °F, low 27 °F 51°27° MarApril: average high 64 °F, low 36 °F 64°36° AprMay: average high 73 °F, low 47 °F 73°47° MayJune: average high 80 °F, low 56 °F 80°56° JunJuly: average high 83 °F, low 60 °F 83°60° JulAugust: average high 82 °F, low 59 °F 82°59° AugSeptember: average high 77 °F, low 51 °F 77°51° SepOctober: average high 65 °F, low 40 °F 65°40° OctNovember: average high 53 °F, low 30 °F 53°30° NovDecember: average high 43 °F, low 25 °F 43°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.42 in precipitation, 9.5 in snowfall 3.4❄10 JanFebruary: 2.84 in precipitation, 8.1 in snowfall 2.8❄8 FebMarch: 3.74 in precipitation, 5.6 in snowfall 3.7❄6 MarApril: 3.38 in precipitation, 0.4 in snowfall 3.4 AprMay: 4.34 in precipitation 4.3 MayJune: 4.17 in precipitation 4.2 JunJuly: 4.31 in precipitation 4.3 JulAugust: 3.88 in precipitation 3.9 AugSeptember: 3.51 in precipitation 3.5 SepOctober: 3.25 in precipitation, 0.2 in snowfall 3.3 OctNovember: 2.94 in precipitation, 0.7 in snowfall 2.9❄1 NovDecember: 3.29 in precipitation, 5.6 in snowfall 3.3❄6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Waynesburg 1 E, PA (11 mi away); precipitation: Waynesburg 1 E, PA (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

154506b
La Belle, PA · 2 mi
153686b
Vestaburg, PA · 2 mi
154336b
East Millsboro, PA · 3 mi
153226b
Clarksville, PA · 3 mi
153256b
Crucible, PA · 3 mi
153576b
Rices Landing, PA · 3 mi
154296b
Denbo, PA · 3 mi
153336b
Fredericktown, PA · 3 mi

Pennsylvania planting zones →

Questions about 15348

What planting zone is ZIP code 15348?

ZIP code 15348 (Millsboro, 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 Millsboro, PA?

The median last spring frost (32 °F) near 15348 is May 3; after May 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Waynesburg 1 E station.

When is the first frost in Millsboro, PA?

The median first fall frost near 15348 is October 15, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 15348?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 15348 get?

About 43.1 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Waynesburg 1 E station).

How hot do summers get in Millsboro, PA?

The average high peaks at 83 °F in July, with about 10 days a year at 90 °F or more.

Did spring come early in Millsboro, PA in 2026?

Spring leaf-out near 15348 came on Mar 10 in 2026, 15 days earlier than the 1991–2020 average (Mar 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Millsboro, PA?

Long-day onions: the longest day near 15348 is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).