Dunbar, PA 15455 Frost Dates
15455, near Dunbar, PA: the frost window
Around 05/01 is the usual last spring frost, about 246 days away. Fall's first freeze usually shows up around 10/13, roughly 164 days after the last spring frost.
Zone 6b (-5 to 0°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 Dunbar, not a forecast for this year.
Stretching the season past the first frost
Dunbar's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/19 and only about 1 year in 10 sees frost after that.
Dunbar against the rest of the dataset
Dunbar's growing season runs about 164 days, ranking 31,064 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,591 of 2,088.
Learn more
Two guides worth reading on 15455: zone vs. frost date, on why Zone 6b and Dunbar's frost date answer different questions, and the frost range, on how to read the range around Dunbar's dates instead of trusting one.