Greencastle, PA 17225 Frost Dates
17225, near Greencastle, PA: the frost window
Around 04/07 is the usual last spring frost, about 222 days away. Fall's first freeze usually shows up around 11/04, roughly 209 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Greencastle 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
Greencastle's growing season runs out in roughly 10 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/07 isn't a guarantee
04/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/21 and only about 1 year in 10 sees frost after that.
Greencastle against the rest of the dataset
Greencastle's growing season runs about 209 days, ranking 15,228 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 84 of 2,088.
Learn more
Two guides worth reading on 17225: local microclimates, on what one yard in Greencastle can differ from the 17225 normal, and zone vs. frost date, on why Zone 7a and Greencastle's frost date answer different questions.