South New Castle, PA 16102 Frost Dates
Frost dates for South New Castle, PA, ZIP 16102
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 10/03, about 140 frost-free days later.
The USDA Plant Hardiness Zone Map puts South New Castle in Zone 6a (-10 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 6a around South New Castle has about 5 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 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How South New Castle compares
About 140 days separate South New Castle's last and first frost, putting it 37,112 of 40,283 ZIP codes nationally. Within PA, it ranks 2,005 of 2,088.
Learn more
the frost range explains how to read the range around South New Castle's dates instead of trusting one, and local microclimates explains what one yard in South New Castle can differ from the 16102 normal.