Penbrook, PA 17103 Frost Dates
17103, near Penbrook, PA: the frost window
The last spring frost here typically falls around 04/09, about 224 days from today. Fall's first freeze usually shows up around 11/01, roughly 205 days after the last spring frost.
Penbrook 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.
Stretching the season past the first frost
Penbrook's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/09 isn't a guarantee
04/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/25 and only about 1 year in 10 sees frost after that.
Penbrook against the rest of the dataset
At roughly 205 frost-free days, Penbrook places 16,294 of 40,283 ZIP codes in this dataset. Within PA, it ranks 154 of 2,088.
Learn more
Two guides worth reading on 17103: local microclimates, on what one yard in Penbrook can differ from the 17103 normal, and zone vs. frost date, on why Zone 7a and Penbrook's frost date answer different questions.