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

Planting zone for 17866 — Coal Township, PA

ZIP code 17866 (Coal Township, Northumberland County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 27 and the first fall frost October 20.

Where ZIP 17866 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 frostApr 27
First frostOct 20
2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Coal Township, 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 Coal Township, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 27median — 50% chance of a later frost
Safe for tender plantsMay 15only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 4
Growing season172 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around November 2.

From the NOAA station Bear Gap, PA — 6 miles away, elevation 1,014 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 17866

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 16 – Mar 30
SpinachSow outdoors · Mar 16 – Apr 6
Broccoli, cabbageStart indoors · Feb 16 – Mar 2
Broccoli, cabbageTransplant · Apr 6 – Apr 20
Onion setsPlant outdoors · Mar 30 – Apr 13
PotatoesPlant outdoors · Apr 6 – Apr 20
LettuceSow outdoors · Mar 30 – Apr 13
Carrots, beetsSow outdoors · Apr 6 – Apr 20
TomatoesStart indoors · Mar 2 – Mar 16
TomatoesTransplant · May 4 – May 18
Peppers, eggplantStart indoors · Feb 16 – Mar 2
Peppers, eggplantTransplant · May 11 – May 25
BeansSow outdoors · May 4 – May 18
Sweet cornSow outdoors · May 4 – May 18
Cucumbers, squashSow outdoors · May 4 – May 18
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 27) 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 17866 came on Mar 31 — 9 days earlier than the 1991–2020 average (Apr 9).

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 Coal Township, PA

The center of ZIP 17866 is mapped as Udorthents, sandstone and shale: 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 17866; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Coal Township, PA

Summer high84 °Faverage high, July
Winter low19 °Faverage low, January
Hot days10days a year at 90 °F or more
Freezing nights127nights a year at 32 °F or less
Growing degree days2,888base 50 °F — the season’s usable heat
Longest day15 h 06 mindaylight on June 21
Shortest day9 h 15 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation48 inper year, rain and melted snow
Snowfall34 inper year; 40 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 35 °F, low 19 °F 35°19° JanFebruary: average high 38 °F, low 22 °F 38°22° FebMarch: average high 48 °F, low 29 °F 48°29° MarApril: average high 61 °F, low 39 °F 61°39° AprMay: average high 71 °F, low 48 °F 71°48° MayJune: average high 79 °F, low 57 °F 79°57° JunJuly: average high 84 °F, low 61 °F 84°61° JulAugust: average high 80 °F, low 60 °F 80°60° AugSeptember: average high 74 °F, low 53 °F 74°53° SepOctober: average high 62 °F, low 42 °F 62°42° OctNovember: average high 50 °F, low 33 °F 50°33° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.54 in precipitation, 9.3 in snowfall 3.5❄9 JanFebruary: 2.53 in precipitation, 8.9 in snowfall 2.5❄9 FebMarch: 3.68 in precipitation, 7.7 in snowfall 3.7❄8 MarApril: 4.27 in precipitation, 0.8 in snowfall 4.3❄1 AprMay: 4.15 in precipitation 4.2 MayJune: 4.77 in precipitation 4.8 JunJuly: 4.36 in precipitation 4.4 JulAugust: 4.09 in precipitation 4.1 AugSeptember: 5.20 in precipitation 5.2 SepOctober: 4.26 in precipitation, 0.4 in snowfall 4.3 OctNovember: 3.50 in precipitation, 1.8 in snowfall 3.5❄2 NovDecember: 3.66 in precipitation, 4.6 in snowfall 3.7❄5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bear Gap, PA (6 mi away); precipitation: Bear Gap, PA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

178366b
Leck Kill, PA · 4 mi
178606b
Paxinos, PA · 5 mi
178816b
Trevorton, PA · 5 mi
178726b
Shamokin, PA · 5 mi
179416b
Klingerstown, PA · 6 mi
178676b
Rebuck, PA · 6 mi
179646b
Pitman, PA · 6 mi
178346b
Kulpmont, PA · 7 mi

Pennsylvania planting zones →

Questions about 17866

What planting zone is ZIP code 17866?

ZIP code 17866 (Coal Township, 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 Coal Township, PA?

The median last spring frost (32 °F) near 17866 is April 27; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bear Gap station.

When is the first frost in Coal Township, PA?

The median first fall frost near 17866 is October 20, giving a median frost-free growing season of 172 days.

When should I plant tomatoes in 17866?

Start tomato seeds indoors around Mar 2 – Mar 16 and set transplants outside around May 4 – May 18, one to three weeks after the median last frost.

How much rain and snow does 17866 get?

About 48 inches of precipitation a year and 34 inches of snowfall (NOAA 1991–2020 normals, Bear Gap station).

How hot do summers get in Coal Township, PA?

The average high peaks at 84 °F in July, with about 10 days a year at 90 °F or more.

Did spring come early in Coal Township, PA in 2026?

Spring leaf-out near 17866 came on Mar 31 in 2026, 9 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Coal Township, PA?

Long-day onions: the longest day near 17866 is 15 h 06 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 17866 change?

Yes. The 2012 USDA map put 17866 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.