Pennsylvania frost dates

Average last spring and first fall frost dates for Pennsylvania’s largest cities, with each city’s USDA hardiness zone.

Reviewed October 2026

Among Pennsylvania’s 20 largest cities, the average last spring frost ranges from Mar 30 in Philadelphia to Apr 30 in Hazleton. Elevation, distance from the coast and city heat all shift the date, so use your own ZIP code below for the closest match.

City	Average last spring frost	Average first fall frost	Frost-free days	Hardiness zone	Weather station used
Philadelphia	Mar 30	Nov 17	232	7b	Phila Franklin Inst, PA, 4 mi
Pittsburgh	Apr 18	Oct 28	193	6b–7a	Pittsburgh Allegheny Co Airport, PA, 7 mi
Allentown	Apr 20	Oct 24	187	7a	Allentown Intl Airport, PA, 4 mi
Reading	Apr 14	Oct 29	198	7a	Reading Spaatz Fld, PA, 3 mi
Erie	Apr 26	Nov 4	192	6b–7a	Erie Intl Airport, PA, 6 mi
Bethlehem	Apr 20	Oct 24	187	7a	Allentown Intl Airport, PA, 5 mi
Scranton	Apr 23	Oct 20	180	6a–7a	Wilkes-Barre Intl Airport, PA, 6 mi
Lancaster	Apr 19	Oct 24	188	7a	Lancaster 2Ne Fltr Plt, PA, 2 mi
Harrisburg	Apr 15	Oct 23	191	7a	Harrisburg 1 Ne, PA
York	Apr 26	Oct 19	176	7a	York 3 Ssw Pump Stn, PA, 3 mi
Wilkes-Barre	Apr 23	Oct 20	180	6a–7a	Wilkes-Barre Intl Airport, PA, 10 mi
Altoona	Apr 25	Oct 21	179	6b	Altoona 3 W, PA, 4 mi
State College	Apr 20	Oct 26	189	6b	State College, PA
Norristown	Apr 8	Oct 31	206	7a–7b	Norristown, PA
Chester	Mar 30	Nov 16	231	7b–8a	Marcus Hook, PA, 3 mi
Bethel Park	Apr 18	Oct 28	193	6b	Pittsburgh Allegheny Co Airport, PA, 6 mi
Easton	Apr 18	Oct 25	190	7a	Phillipsburg-Easton Brg, NJ
Hazleton	Apr 30	Oct 22	175	6b	Mahanoy City 2 N, PA, 12 mi
Monroeville	Apr 22	Oct 25	186	6b	Murrysville 2 Sw, PA, 2 mi
Williamsport	Apr 25	Oct 24	182	6b	Williamsport 2, PA, 3 mi

Frost dates are the dates after (spring) or before (fall) which the chance of a 32°F freeze is below 50%, from NOAA’s 1991–2020 U.S. Climate Normals for the weather station nearest each city’s center. Zones are from the 2023 USDA Plant Hardiness Zone Map for the ZIP codes around each city; a range means nearby ZIP codes differ. Cities are the 20 largest by Census Bureau 2024 population estimates.

An average is not a guarantee. There’s still about a 1 in 2 chance of frost after the average last spring date. Many gardeners wait an extra week or two before setting out tomatoes, peppers and basil, and keep covers handy.

Planting dates for Philadelphia

Timed from Philadelphia’s average last frost of Mar 30, using University of New Hampshire Extension’s planting guidance. For your exact dates, enter your ZIP code in the calendar below.

Crop	Start seeds indoors	Plant outside
Tomatoes	Feb 9 to Feb 23	Apr 6 to Apr 13
Peppers	Feb 2 to Feb 16	Apr 13
Lettuce	Jan 26 to Feb 2	Mar 2 to Mar 9
Broccoli	Jan 19 to Feb 2	Mar 2 to Mar 16
Cucumbers	Mar 9 to Mar 16	Apr 6 to Apr 13
Basil	Feb 16 to Mar 2	Apr 13

When to plant, for your garden

Your seed-starting and planting dates, timed from your last spring frost. Full calendar, 12 crops.

ZIP code

Last frost date

Enter your ZIP code to look up your average last frost date and hardiness zone, or type the date in yourself.

Frost dates: NOAA U.S. Climate Normals, 1991–2020. Hardiness zones: USDA Plant Hardiness Zone Map, 2023, ZIP code data from PRISM Group, Oregon State University, prism.oregonstate.edu, accessed Oct. 20, 2026.

More about frost dates

How to find your last frost date, and what your zone means · Full planting calendar · How to start seeds indoors

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