Swarthmore, PA 19081 Frost Dates
When can you plant in Swarthmore, PA?
The last spring frost here typically falls around 04/02, about 217 days from today. The first fall frost typically arrives around 11/10, about 224 frost-free days later.
Swarthmore 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
About 11 weeks of growing season left in Swarthmore before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/02 isn't a guarantee
04/02 is the middle of 30 years of NOAA records, not a promise. Plant by 03/19 and you're betting against frost in roughly 9 years out of 10. 04/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Swarthmore compares
About 224 days separate Swarthmore's last and first frost, putting it 11,828 of 40,283 ZIP codes nationally. Within PA, it ranks 18 of 2,088.
Learn more
zone vs. frost date covers why Zone 7b and Swarthmore's frost date answer different questions. the frost range covers how to read the range around Swarthmore's dates instead of trusting one.