Williamsport, PA 17705 Frost Dates
When can you plant in Williamsport, PA?
Typically, the last spring freeze lands around 04/24, roughly 239 days out. The first fall frost typically arrives around 10/23, about 180 frost-free days later.
Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Williamsport, not a forecast for this year.
What to do before the first frost
About 8 weeks of growing season left in Williamsport before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/24 isn't a guarantee
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williamsport compares
About 180 days separate Williamsport's last and first frost, putting it 24,789 of 40,283 ZIP codes nationally. Within PA, it ranks 843 of 2,088.
Learn more
zone vs. frost date covers why Zone 6b and Williamsport's frost date answer different questions. the frost range covers how to read the range around Williamsport's dates instead of trusting one.