Bryn Athyn, PA 19009 Frost Dates
Frost dates for Bryn Athyn, PA, ZIP 19009
The last spring frost here typically falls around 04/04, about 219 days from today. The first fall frost typically arrives around 11/07, about 216 frost-free days later.
Bryn Athyn 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 Bryn Athyn has about 10 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
04/04 is the middle of 30 years of NOAA records, not a promise. Plant by 03/21 and you're betting against frost in roughly 9 years out of 10. 04/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bryn Athyn compares
About 216 days separate Bryn Athyn's last and first frost, putting it 13,847 of 40,283 ZIP codes nationally. Within PA, it ranks 75 of 2,088.
Learn more
the frost range explains how to read the range around Bryn Athyn's dates instead of trusting one, and local microclimates explains what one yard in Bryn Athyn can differ from the 19009 normal.