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

Planting zone for 15864 — Summerville, PA

ZIP code 15864 (Summerville, Jefferson County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 10 and the first fall frost October 12.

Where ZIP 15864 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostMay 10
First frostOct 12
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Summerville, 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 Summerville, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 10median — 50% chance of a later frost
Safe for tender plantsMay 28only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 30
Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 26.

From the NOAA station Putneyville 2 Se Dam, PA — 13 miles away, elevation 1,280 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 15864

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 29 – Apr 12
SpinachSow outdoors · Mar 29 – Apr 19
Broccoli, cabbageStart indoors · Mar 1 – Mar 15
Broccoli, cabbageTransplant · Apr 19 – May 3
Onion setsPlant outdoors · Apr 12 – Apr 26
PotatoesPlant outdoors · Apr 19 – May 3
LettuceSow outdoors · Apr 12 – Apr 26
Carrots, beetsSow outdoors · Apr 19 – May 3
TomatoesStart indoors · Mar 15 – Mar 29
TomatoesTransplant · May 17 – May 31
Peppers, eggplantStart indoors · Mar 1 – Mar 15
Peppers, eggplantTransplant · May 24 – Jun 7
BeansSow outdoors · May 17 – May 31
Sweet cornSow outdoors · May 17 – May 31
Cucumbers, squashSow outdoors · May 17 – May 31
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 10) and first fall frost (Oct 12) 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 15864 came on Mar 21 — 17 days earlier than the 1991–2020 average (Apr 7).

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).

Soil in Summerville, PA

The soil mapped at the center of ZIP 15864 is Ernest — moderately decomposed plant material, moderately well drained.

TextureModerately decomposed plant materialtop layer
pH4.5strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter60%high
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Ernest 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 15864; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Summerville, PA

Summer high82 °Faverage high, July
Winter low17 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights152nights a year at 32 °F or less
Growing degree days2,597base 50 °F — the season’s usable heat
Longest day15 h 08 mindaylight on June 21
Shortest day9 h 13 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.7 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 17 °F 35°17° JanFebruary: average high 38 °F, low 18 °F 38°18° FebMarch: average high 47 °F, low 24 °F 47°24° MarApril: average high 61 °F, low 35 °F 61°35° AprMay: average high 71 °F, low 45 °F 71°45° MayJune: average high 78 °F, low 54 °F 78°54° JunJuly: average high 82 °F, low 58 °F 82°58° JulAugust: average high 81 °F, low 57 °F 81°57° AugSeptember: average high 74 °F, low 50 °F 74°50° SepOctober: average high 62 °F, low 39 °F 62°39° OctNovember: average high 50 °F, low 30 °F 50°30° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.32 in precipitation 3.3 JanFebruary: 2.86 in precipitation 2.9 FebMarch: 3.24 in precipitation 3.2 MarApril: 3.96 in precipitation 4.0 AprMay: 3.99 in precipitation 4.0 MayJune: 5.03 in precipitation 5.0 JunJuly: 4.32 in precipitation 4.3 JulAugust: 4.03 in precipitation 4.0 AugSeptember: 4.08 in precipitation 4.1 SepOctober: 3.57 in precipitation 3.6 OctNovember: 3.57 in precipitation 3.6 NovDecember: 3.69 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Putneyville 2 Se Dam, PA (13 mi away); precipitation: Brookville 5.3 Ssw, PA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

162406a
Mayport, PA · 5 mi
162246a
Fairmount City, PA · 6 mi
157846a
Worthville, PA · 6 mi
157706a
Ringgold, PA · 7 mi
162306a
Hawthorn, PA · 7 mi
157766a
Sprankle Mills, PA · 8 mi
157306a
Coolspring, PA · 8 mi
158296a
Corsica, PA · 8 mi

Pennsylvania planting zones →

Questions about 15864

What planting zone is ZIP code 15864?

ZIP code 15864 (Summerville, PA) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Summerville, PA?

The median last spring frost (32 °F) near 15864 is May 10; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Putneyville 2 Se Dam station.

When is the first frost in Summerville, PA?

The median first fall frost near 15864 is October 12, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 15864?

Start tomato seeds indoors around Mar 15 – Mar 29 and set transplants outside around May 17 – May 31, one to three weeks after the median last frost.

How much rain and snow does 15864 get?

About 45.7 inches of precipitation a year (NOAA 1991–2020 normals, Brookville 5.3 Ssw station).

How hot do summers get in Summerville, PA?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 15864 have?

The USDA soil survey maps Ernest at the center of ZIP 15864: moderately decomposed plant material, moderately well drained, pH about 4.5 (strongly acidic).

Did spring come early in Summerville, PA in 2026?

Spring leaf-out near 15864 came on Mar 21 in 2026, 17 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Summerville, PA?

Long-day onions: the longest day near 15864 is 15 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 15864 change?

Yes. The 2012 USDA map put 15864 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.