Harrisburg, PA 17101 Frost Dates
Frost dates for Harrisburg, PA, ZIP 17101
The last spring frost here typically falls around 04/09, about 224 days from today. The first fall frost typically arrives around 11/01, about 205 frost-free days later.
Harrisburg 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.
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.
How much risk comes with planting early here
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 16,162 of 40,283 ZIP codes nationally. Within PA, it ranks 112 of 2,088.
Learn more
local microclimates explains what one yard in Harrisburg can differ from the 17101 normal, and zone vs. frost date explains why Zone 7a and Harrisburg's frost date answer different questions.