Duncansville, PA 16635 Frost Dates
Frost dates for Duncansville, PA, ZIP 16635
Typically, the last spring freeze lands around 04/23, roughly 238 days out. The first fall frost typically arrives around 10/21, about 177 frost-free days later.
The USDA Plant Hardiness Zone Map puts Duncansville 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 Duncansville 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.
How much risk comes with planting early here
04/23 is the middle of 30 years of NOAA records, not a promise. Plant by 04/08 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 Duncansville compares
Duncansville's growing season runs about 177 days, ranking 26,172 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 965 of 2,088.
Learn more
the frost range explains how to read the range around Duncansville's dates instead of trusting one, and local microclimates explains what one yard in Duncansville can differ from the 16635 normal.