Harrisburg, PA 17127 Frost Dates
Frost dates for Harrisburg, PA, ZIP 17127
Around 04/09 is the usual last spring frost, about 224 days away. The first fall frost typically arrives around 11/01, about 205 frost-free days later.
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.
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.
Why 04/09 isn't a guarantee
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 16,173 of 40,283 ZIP codes nationally. Within PA, it ranks 123 of 2,088.
Learn more
the frost range explains how to read the range around Harrisburg's dates instead of trusting one, and local microclimates explains what one yard in Harrisburg can differ from the 17127 normal.