Penn, PA 15675 Frost Dates
When can you plant in Penn, PA?
Around 05/01 is the usual last spring frost, about 246 days away. The first fall frost typically arrives around 10/13, about 164 frost-free days later.
The USDA Plant Hardiness Zone Map puts Penn in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 7 weeks of growing season left in Penn before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/17 and you're betting against frost in roughly 9 years out of 10. 05/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Penn compares
About 164 days separate Penn's last and first frost, putting it 31,105 of 40,283 ZIP codes nationally. Within PA, it ranks 1,596 of 2,088.
Learn more
local microclimates covers what one yard in Penn can differ from the 15675 normal. zone vs. frost date covers why Zone 6b and Penn's frost date answer different questions.