Williamstown, PA 17098 Frost Dates
Frost dates for Williamstown, PA, ZIP 17098
Typically, the last spring freeze lands around 04/27, roughly 242 days out. The first fall frost typically arrives around 10/20, about 172 frost-free days later.
The USDA Plant Hardiness Zone Map puts Williamstown 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
Zone 6b around Williamstown 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.
The actual range around Williamstown's last frost
04/27 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. 05/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williamstown compares
Williamstown's growing season runs about 172 days, ranking 28,385 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,383 of 2,088.
Learn more
local microclimates explains what one yard in Williamstown can differ from the 17098 normal, and zone vs. frost date explains why Zone 6b and Williamstown's frost date answer different questions.