Williamsport, PA 17703 Frost Dates
Frost dates for Williamsport, PA, ZIP 17703
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
Zone 6b around Williamsport has about 8 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
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
At roughly 180 frost-free days, Williamsport places 24,788 of 40,283 ZIP codes in this dataset. Within PA, it ranks 842 of 2,088.
Learn more
zone vs. frost date explains why Zone 6b and Williamsport's frost date answer different questions, and the frost range explains how to read the range around Williamsport's dates instead of trusting one.