New Castle, PA 16103 Frost Dates
16103, near New Castle, PA: the frost window
Typically, the last spring freeze lands around 05/15, roughly 260 days out. Fall's first freeze usually shows up around 10/03, roughly 140 days after the last spring frost.
New Castle sits in USDA Zone 6b (-5 to 0°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.
Stretching the season past the first frost
New Castle's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
New Castle against the rest of the dataset
About 140 days separate New Castle's last and first frost, putting it 37,022 of 40,283 ZIP codes nationally. Within PA, it ranks 1,971 of 2,088.
Learn more
Two guides worth reading on 16103: the frost range, on how to read the range around New Castle's dates instead of trusting one, and local microclimates, on what one yard in New Castle can differ from the 16103 normal.