Harrisburg, PA 17130 Frost Dates
Frost dates for Harrisburg, PA, ZIP 17130
Typically, the last spring freeze lands around 04/09, roughly 224 days out. The first fall frost typically arrives around 11/01, about 205 frost-free days later.
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 Harrisburg, not a forecast for this year.
What to do before the first frost
Zone 7a around Harrisburg has about 9 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Harrisburg's last frost
04/09 is the middle of 30 years of NOAA records, not a promise. Plant by 03/27 and you're betting against frost in roughly 9 years out of 10. 04/25 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Harrisburg compares
About 205 days separate Harrisburg's last and first frost, putting it 16,175 of 40,283 ZIP codes nationally. Within PA, it ranks 125 of 2,088.
Learn more
local microclimates explains what one yard in Harrisburg can differ from the 17130 normal, and zone vs. frost date explains why Zone 7a and Harrisburg's frost date answer different questions.