Wilkinsburg, PA 15221 Frost Dates
15221, near Wilkinsburg, PA: the frost window
Typically, the last spring freeze lands around 04/18, roughly 233 days out. Fall's first freeze usually shows up around 10/28, roughly 193 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Wilkinsburg in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Wilkinsburg's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Wilkinsburg against the rest of the dataset
Wilkinsburg's growing season runs about 193 days, ranking 19,761 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 415 of 2,088.
Learn more
Two guides worth reading on 15221: zone vs. frost date, on why Zone 6b and Wilkinsburg's frost date answer different questions, and the frost range, on how to read the range around Wilkinsburg's dates instead of trusting one.