Orrstown, PA 17251 Frost Dates
Orrstown, PA: when does the frost end?
Typically, the last spring freeze lands around 04/15, roughly 230 days out. Fall's first freeze usually shows up around 10/27, roughly 194 days after the last spring frost.
Zone 7a (0 to 5°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Orrstown, not a forecast for this year.
Stretching the season past the first frost
With roughly 9 weeks until Orrstown's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Orrstown's last frost
04/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/04 and only about 1 year in 10 sees frost after that.
Orrstown against the rest of the dataset
Orrstown's growing season runs about 194 days, ranking 19,625 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 403 of 2,088.
Learn more
Before leaning on 17251's figures: zone vs. frost date explains why Zone 7a and Orrstown's frost date answer different questions, while the frost range explains how to read the range around Orrstown's dates instead of trusting one.