Harrisburg, PA 17126 Frost Dates
17126, near Harrisburg, 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.
The USDA Plant Hardiness Zone Map puts Harrisburg 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
Harrisburg'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.
How much risk comes with planting early here
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.
Harrisburg against the rest of the dataset
At roughly 205 frost-free days, Harrisburg places 16,172 of 40,283 ZIP codes in this dataset. Within PA, it ranks 122 of 2,088.
Learn more
Two guides worth reading on 17126: zone vs. frost date, on why Zone 7a and Harrisburg's frost date answer different questions, and the frost range, on how to read the range around Harrisburg's dates instead of trusting one.