Cornwall, PA 17085 Frost Dates
When can you plant in Cornwall, PA?
Around 04/20 is the usual last spring frost, about 235 days away. The first fall frost typically arrives around 10/25, about 185 frost-free days later.
Cornwall sits in USDA Zone 7a (0 to 5°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 8 weeks of growing season left in Cornwall before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/05 and you're betting against frost in roughly 9 years out of 10. 05/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Cornwall compares
Cornwall's growing season runs about 185 days, ranking 23,142 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 696 of 2,088.
Learn more
zone vs. frost date covers why Zone 7a and Cornwall's frost date answer different questions. the frost range covers how to read the range around Cornwall's dates instead of trusting one.