Philadelphia, PA 19197 Frost Dates
19197, near Philadelphia, PA: the frost window
Around 04/15 is the usual last spring frost, about 230 days away. Fall's first freeze usually shows up around 10/31, roughly 199 days after the last spring frost.
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.
Stretching the season past the first frost
Philadelphia's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Philadelphia against the rest of the dataset
At roughly 199 frost-free days, Philadelphia places 17,965 of 40,283 ZIP codes in this dataset. Within PA, it ranks 278 of 2,088.
Learn more
Two guides worth reading on 19197: local microclimates, on what one yard in Philadelphia can differ from the 19197 normal, and zone vs. frost date, on why Zone 7b and Philadelphia's frost date answer different questions.