USDA zone 6a in Pennsylvania
USDA plant hardiness zone 6a covers 67 locations across Pennsylvania (average annual extreme minimum −10 to −5 °F): Archbald, PA, Bear Rocks, PA, Blossburg, PA, Byrnedale, PA, Carbondale, PA, Clarence, PA, and 61 more. Average last spring frost across this group ranges April 16 (Seltzer) to May 22 (Columbus), and growing seasons run 130–192 days (Clarence to Edinboro) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Pennsylvania location's own frost dates; the printable planting calendar uses Byrnedale, this group's median-season location.
- USDA zone
- 6a−10 to −5 °F
- Last frost range
- Apr 16–May 22avg, 32°F
- First frost range
- Sep 27–Nov 4avg, 32°F
- Growing season range
- 130–192days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Archbald | Jessup, Harveys Lake, Blakely, Silkworth, Dalton, Moscow, +10 more | Wilkes-barre Intl Ap | Apr 23 | Oct 20 | 178 |
| Bear Rocks | Donegal | Donegal 2 Nw | Apr 30 | Oct 17 | 170 |
| Blossburg | Canton, Arnot, Morris Run, Troy, Alba, Liberty, +1 more | Canton | May 16 | Oct 2 | 139 |
| Byrnedale * | — | Emporium | May 7 | Oct 15 | 160 |
| Carbondale | Waymart, Mayfield, Prompton, Nicholson, Harford, Forest, +1 more | Pleasant Mt 1 W | May 14 | Oct 1 | 140 |
| Clarence | — | Clarence | May 21 | Sep 27 | 130 |
| Columbus | — | Chandlers Valley 1se | May 22 | Sep 30 | 131 |
| Confluence | Seven Springs, Friendsville, Ursina, Addison, Accident, Ohiopyle, +3 more | Confluence 1 Sw Dam | Apr 30 | Oct 18 | 171 |
| Conneautville | Albion, Cranesville, Springboro | Springboro 3 Wnw | May 8 | Oct 16 | 160 |
| Corry | Titusville, Hydetown, Centerville, Pleasantville, Spartansburg, Townville | Titusville Wtr Wks | May 12 | Oct 10 | 149 |
| Driftwood | Sinnamahoning, Karthaus | Stevenson Dam | May 10 | Oct 16 | 157 |
| Eagles Mere | Forksville, Waller, Pikes Creek, Laporte, Mehoopany, Jamison, +1 more | Laporte | May 6 | Oct 7 | 154 |
| East Side | Freeland | Francis E Walter Dam | May 7 | Oct 6 | 153 |
| Edinboro | North East, Waterford, McKean, Wattsburg | Erie Intl Ap | Apr 26 | Nov 4 | 192 |
| Farmington | Deer Lake, Seven Springs, Dunbar, Ohiopyle, Brandonville, Bruceton Mills | Chalk Hill 2 Ene | May 19 | Oct 1 | 135 |
| Friedens | Jennerstown, Edie, Ligonier, Gray, Acosta, Donegal, +2 more | Laurel Summit | May 6 | Oct 12 | 159 |
| Gallitzin | Cresson | Altoona 3 W | Apr 25 | Oct 21 | 176 |
| Garden View | Salladasburg, Liberty | Williamsport 2 | Apr 25 | Oct 24 | 181 |
| Gilberton | Harleigh | Mahanoy City 2 N | Apr 30 | Oct 22 | 175 |
| Grampian | — | Grampian 1e | May 4 | Oct 13 | 160 |
| Great Bend | — | Deposit | May 12 | Oct 9 | 152 |
| Heilwood | Glen Campbell, Dixonville, Commodore, Alverda, Marion Center, Clymer, +3 more | Indiana 3 Se | May 8 | Oct 13 | 157 |
| Hopwood | — | Uniontown 1 Ne | Apr 30 | Oct 18 | 171 |
| Hyner | Renovo, Salladasburg, North Bend | Renovo | Apr 30 | Oct 22 | 173 |
| Indian Lake | Central, Shanksville | Shawnee Sp | May 4 | Oct 10 | 158 |
| Indian Mountain Lake | Towamensing Trails, Pocono Pines, Big Bass Lake, Pocono Springs, Mount Pocono, Emerald Lakes, +3 more | Mt Pocono Mountains Ap | May 6 | Oct 8 | 154 |
| Joffre | — | Pittsburgh Intl Ap | Apr 23 | Oct 23 | 181 |
| Lanse | Winburne, Kylertown, Grassflat, West Decatur, Madera, Bigler, +11 more | Philipsburg 2 S | May 13 | Oct 1 | 142 |
| Little Meadows | Waverly, Sayre, Athens, East Smithfield, Van Etten, Rome, +1 more | Waverly | May 6 | Oct 10 | 157 |
| Mansfield | Millerton, Lawrenceville, Tioga | Cowanesque Dam | May 9 | Oct 12 | 155 |
| Marienville | Punxsutawney, Brookville, Luthersburg, Sykesville, Reynoldsville, Penfield, +6 more | Dubois Jefferson Co Ap | May 6 | Oct 14 | 160 |
| Marienville | Crown, Vowinckel, Hasson Heights, Tionesta, Tidioute, Pleasantville, +3 more | Tionesta 2 Se Lake | May 1 | Oct 25 | 176 |
| Mercer | — | Mercer | May 15 | Oct 3 | 140 |
| Montoursville | — | Williamsport | Apr 24 | Oct 23 | 180 |
| New Columbus | — | Benton 3 Ne | May 4 | Oct 11 | 159 |
| North Apollo | — | Salina 3 W | Apr 29 | Oct 20 | 171 |
| Northern Cambria | Nanty-Glo, Colver, Elmora, Spring Hill, Loretto, Alverda, +8 more | Ebensburg Sewage Plt | May 17 | Oct 2 | 136 |
| Pocono Woodland Lakes | Monticello, Eldred, Barryville | Port Jervis | May 5 | Oct 10 | 158 |
| Punxsutawney | Rural Valley, Rossiter, Distant, Hawthorn, Timblin, Marion Center, +7 more | Putneyville 2 Se Dam | May 10 | Oct 12 | 155 |
| Pymatuning North | — | Linesville 1 S | Apr 30 | Oct 23 | 177 |
| Reynolds Heights | Pymatuning South, Kinsman Center, Greenville, Andover, Hartstown, Adamsville, +1 more | Jamestown 2 Nw | May 4 | Oct 14 | 161 |
| Rural Valley | Manorville, Ford Cliff | Ford City 4 S Dam | May 4 | Oct 16 | 164 |
| Russell | Warren, Youngsville, Clarendon | Warren | May 4 | Oct 21 | 168 |
| Saegertown | Harmonsburg, Cochranton, Cambridge Springs, Kerrtown, Conneaut Lake, Guys Mills, +3 more | Port Meadville Ap | Apr 30 | Oct 23 | 175 |
| Seltzer | — | Hamburg | Apr 16 | Oct 25 | 189 |
| Seven Springs | — | Hidden Valley | May 2 | Oct 17 | 168 |
| Shanor-Northvue | Prospect, Meadowood, East Butler, Saxonburg, Callery, Chicora, +2 more | Butler 2 Sw | May 7 | Oct 14 | 159 |
| Sligo | Parker, Emlenton, Knox, Leeper, Strattanville, Corsica, +5 more | Clarion 3 Sw | May 9 | Oct 11 | 154 |
| Snow Shoe | — | State College | Apr 20 | Oct 26 | 187 |
| Somerset | Berlin, Meyersdale, Garrett, Salisbury | Meyersdale 2 Ssw | May 12 | Oct 5 | 146 |
| Springville | Hallstead | Montrose | May 14 | Oct 2 | 141 |
| Sproul | — | Altoona Blair Co Ap | Apr 23 | Oct 21 | 177 |
| Sugarcreek | Oil, Stoneboro, Seneca, Kennerdell, Polk, Utica, +4 more | Franklin | May 2 | Oct 23 | 171 |
| The Hideout | Masthope, Fawn Lake Forest, Narrowsburg, Wallenpaupack Lake Estates, White Mills, Lake Wallenpaupack Estates, +4 more | Hawley 1 E | May 10 | Oct 4 | 146 |
| Towanda | LeRaysville, Ulster, Wyalusing, Meshoppen, Burlington, Rome, +3 more | Towanda 1 S | May 2 | Oct 15 | 165 |
| Union | Mill, Wattsburg | Union City Filtration Plant | May 7 | Oct 10 | 155 |
| Vinco | Jerome, Davidsville, Beaverdale, Elim, Windber, St. Michael, +5 more | Johnstown Cambria Co Ap | Apr 29 | Oct 21 | 176 |
| Vowinckel | — | Cooksburg 2 Nw | May 13 | Oct 7 | 143 |
| Weedville | — | Ridgway | May 13 | Oct 11 | 150 |
| Wellsboro | Galeton, Hyner, Westfield, Knoxville, Liberty | Wellsboro 4 Sw | May 10 | Oct 5 | 148 |
| West Liberty | Barkeyville, Grove, Bruin, Eau Claire, Jackson Center, Clintonville, +5 more | Slippery Rock 1 Ssw | May 7 | Oct 14 | 158 |
| Westland | — | Washington 3 Ne | Apr 24 | Oct 23 | 181 |
| Westover | Glen Hope, Burnside, Emeigh, St. Benedict, Glen Campbell, Irvona, +10 more | Prince Gallitzin Sp | May 10 | Oct 5 | 149 |
| Wind Ridge | Green Hills, Rogersville | Waynesburg 1 E | May 3 | Oct 15 | 164 |
| Wind Ridge | Cameron, New Freeport | Moundsville | Apr 26 | Oct 21 | 177 |
| Woodland | Luthersburg, Hyde, Plymptonville, Frenchville, Glen Richey | Clearfield Lawrence Ap | May 4 | Oct 11 | 161 |
| Woolrich | Jersey Shore | Lock Haven Sewage Plt | Apr 30 | Oct 20 | 173 |
* Byrnedale is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Byrnedale, representative)
Computed from Byrnedale's average frost dates — the median-season location in this Pennsylvaniazone 6a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 12 – Mar 26 | May 14 – May 21 | Jul 13 – Aug 2 | — | matures comfortably |
| Pepper | Very tender | Feb 26 – Mar 12 | May 21 – May 28 | Jul 20 – Aug 19 | — | matures comfortably |
| Cucumber | Tender | Apr 9 – Apr 16 | May 14 – May 21 | Jul 3 – Jul 23 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 14 – May 21 | Jun 28 – Jul 13 | — | matures comfortably |
| Bush bean | Tender | — | May 14 – May 21 | Jul 3 – Jul 13 | Aug 16 – Aug 26 | matures comfortably |
| Sweet corn | Tender | — | May 7 – May 21 | Jul 6 – Aug 5 | — | matures comfortably |
| Basil | Very tender | Mar 26 – Apr 9 | May 14 – May 21 | Jun 13 – Jun 28 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 26 – Apr 9 | Apr 9 – Apr 23 | May 24 – Jun 8 | Aug 2 – Aug 17 | matures comfortably |
| Pea | Hardy | — | Mar 26 – Apr 9 | May 20 – Jun 4 | Jul 23 – Aug 7 | matures comfortably |
| Spinach | Hardy | — | Mar 26 – Apr 9 | May 5 – May 15 | Aug 12 – Aug 22 | matures comfortably |
| Carrot | Half-hardy | — | Apr 16 – Apr 23 | Jun 15 – Jul 5 | Jul 13 – Aug 2 | matures comfortably |
| Broccoli | Half-hardy | Mar 12 – Mar 26 | Apr 9 – Apr 23 | Jun 3 – Jun 23 | Jul 18 – Aug 7 | matures comfortably |
Which crops fit this growing season
Using Byrnedale's own 160-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Byrnedale)
From NOAA's 1991–2020 Climate Normals at station USC00362629. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 19 | May 31 | Oct 3 | Oct 16 | 137 |
| 32°F (freeze) | May 7 | May 23 | Oct 15 | Nov 1 | 160 |
| 28°F | Apr 27 | May 13 | Oct 28 | Nov 9 | 183 |
| 24°F | Apr 13 | May 2 | Nov 7 | Nov 18 | 208 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 67 locations is 2,563; Byrnedale's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,563 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,630 | cool-season crops (brassicas, greens) |
Hardiness zone 6a in Pennsylvania
Zone 6a means an average annual extreme minimum winter temperature of about −10 to −5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Pennsylvania spans 7 hardiness zones in this dataset — see all Pennsylvania locations for the full range, including zones5a, 5b, 6b, 7a, 7b, 8a.
Explore zone 6a in other states at zone 6a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 6a mean in Pennsylvania?
- Zone 6a means an average annual extreme minimum winter temperature of −10 to −5 °F — the standard USDA measure of which perennials survive winter. 67 locations in Pennsylvania fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Pennsylvania's zone 6a is the growing season longest?
- Edinboro runs the longest season on this page at about 192 days; Clarence is shortest at about 130 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Pennsylvania's zone 6a?
- Using Byrnedale's frost dates (this page's median-season location): start seeds indoors about Mar 12 – Mar 26, then transplant outside about May 14 – May 21. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Pennsylvania's zone 6a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 67 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.