Philadelphia, PA 19181 Frost Dates
Frost dates for Philadelphia, PA, ZIP 19181
The last spring frost here typically falls around 04/15, about 230 days from today. The first fall frost typically arrives around 10/31, about 199 frost-free days later.
Philadelphia sits in USDA Zone 7b (5 to 10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 7b around Philadelphia has about 9 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
04/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/01 and you're betting against frost in roughly 9 years out of 10. 05/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Philadelphia compares
At roughly 199 frost-free days, Philadelphia places 17,954 of 40,283 ZIP codes in this dataset. Within PA, it ranks 267 of 2,088.
Learn more
the frost range explains how to read the range around Philadelphia's dates instead of trusting one, and local microclimates explains what one yard in Philadelphia can differ from the 19181 normal.