Lancaster, PA 17605 Frost Dates
Lancaster, PA: when does the frost end?
Around 04/18 is the usual last spring frost, about 233 days away. Fall's first freeze usually shows up around 10/25, roughly 186 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Lancaster in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 8 weeks until Lancaster's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
Lancaster against the rest of the dataset
At roughly 186 frost-free days, Lancaster places 22,697 of 40,283 ZIP codes in this dataset. Within PA, it ranks 635 of 2,088.
Learn more
Before leaning on 17605's figures: local microclimates explains what one yard in Lancaster can differ from the 17605 normal, while zone vs. frost date explains why Zone 7a and Lancaster's frost date answer different questions.