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

Planting zone for 17340 — Littlestown, PA

ZIP code 17340 (Littlestown, Adams 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 20.

Where ZIP 17340 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 24
First frostOct 20
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 Littlestown, 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 Littlestown, 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 11only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 6
Growing season177 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 31.

From the NOAA station Hanover 4 Sw, PA — 4 miles away, elevation 558 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 17340

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 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 20) 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 17340 came on Mar 21 — 5 days earlier than the 1991–2020 average (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.

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 Littlestown, PA.

Soil in Littlestown, PA

The soil mapped at the center of ZIP 17340 is Croton — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of local importanceUSDA classification

Map unit: Croton silt loam, occasionally ponded, 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 17340; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Littlestown, PA

Summer high85 °Faverage high, July
Winter low21 °Faverage low, January
Hot days18days a year at 90 °F or more
Freezing nights122nights a year at 32 °F or less
Growing degree days3,289base 50 °F — the season’s usable heat
Longest day14 h 59 mindaylight on June 21
Shortest day9 h 21 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation45.4 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 39 °F, low 21 °F 39°21° JanFebruary: average high 42 °F, low 23 °F 42°23° FebMarch: average high 50 °F, low 30 °F 50°30° MarApril: average high 63 °F, low 40 °F 63°40° AprMay: average high 72 °F, low 50 °F 72°50° MayJune: average high 81 °F, low 60 °F 81°60° JunJuly: average high 85 °F, low 64 °F 85°64° JulAugust: average high 84 °F, low 62 °F 84°62° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 66 °F, low 43 °F 66°43° OctNovember: average high 54 °F, low 33 °F 54°33° NovDecember: average high 44 °F, low 26 °F 44°26° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.26 in precipitation 3.3 JanFebruary: 2.70 in precipitation 2.7 FebMarch: 3.78 in precipitation 3.8 MarApril: 3.76 in precipitation 3.8 AprMay: 4.31 in precipitation 4.3 MayJune: 3.90 in precipitation 3.9 JunJuly: 4.13 in precipitation 4.1 JulAugust: 3.75 in precipitation 3.8 AugSeptember: 5.11 in precipitation 5.1 SepOctober: 3.86 in precipitation 3.9 OctNovember: 3.22 in precipitation 3.2 NovDecember: 3.64 in precipitation 3.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hanover 4 Sw, PA (4 mi away); precipitation: Taneytown 4.1 Ne, MD (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

217877a
Taneytown, MD · 6 mi
173446b
Mc Sherrystown, PA · 6 mi
173317a
Hanover, PA · 8 mi
173257a
Gettysburg, PA · 8 mi
173327a
Hanover, PA · 8 mi
173336b
Hanover, PA · 8 mi
173357a
Hanover, PA · 8 mi
211587a
Westminster, MD · 8 mi

Pennsylvania planting zones →

Questions about 17340

What planting zone is ZIP code 17340?

ZIP code 17340 (Littlestown, 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 Littlestown, PA?

The median last spring frost (32 °F) near 17340 is April 24; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hanover 4 Sw station.

When is the first frost in Littlestown, PA?

The median first fall frost near 17340 is October 20, giving a median frost-free growing season of 177 days.

When should I plant tomatoes in 17340?

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 17340 get?

About 45.4 inches of precipitation a year (NOAA 1991–2020 normals, Taneytown 4.1 Ne station).

How hot do summers get in Littlestown, PA?

The average high peaks at 85 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 17340 have?

The USDA soil survey maps Croton at the center of ZIP 17340: silt loam, poorly drained, pH about 6.2 (slightly acidic).

Did spring come early in Littlestown, PA in 2026?

Spring leaf-out near 17340 came on Mar 21 in 2026, 5 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Littlestown, PA?

Intermediate onions: the longest day near 17340 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 17340 change?

Yes. The 2012 USDA map put 17340 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.