Lancaster, PA 17503 Frost Dates
Frost dates for Lancaster, PA, ZIP 17503
Typically, the last spring freeze lands around 04/18, roughly 233 days out. The first fall frost typically arrives around 10/25, about 186 frost-free days later.
Lancaster 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
Zone 7a around Lancaster has about 8 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
04/18 is the middle of 30 years of NOAA records, not a promise. Plant by 04/04 and you're betting against frost in roughly 9 years out of 10. 05/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Lancaster compares
Lancaster's growing season runs about 186 days, ranking 22,689 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 627 of 2,088.
Learn more
zone vs. frost date explains why Zone 7a and Lancaster's frost date answer different questions, and the frost range explains how to read the range around Lancaster's dates instead of trusting one.