Williamstown, PA 17968 Frost Dates
Frost dates for Williamstown, PA, ZIP 17968
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.
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 Williamstown, not a forecast for this year.
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 28,386 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,384 of 2,088.
Learn more
zone vs. frost date explains why Zone 6b and Williamstown's frost date answer different questions, and the frost range explains how to read the range around Williamstown's dates instead of trusting one.