Philadelphia, PA 19140 Frost Dates
19140, near Philadelphia, PA: the frost window
Typically, the last spring freeze lands around 04/15, roughly 230 days out. 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
About 199 days separate Philadelphia's last and first frost, putting it 17,942 of 40,283 ZIP codes nationally. Within PA, it ranks 255 of 2,088.
Learn more
Two guides worth reading on 19140: zone vs. frost date, on why Zone 7b and Philadelphia's frost date answer different questions, and the frost range, on how to read the range around Philadelphia's dates instead of trusting one.