Swissvale, PA 15218 Frost Dates
15218, near Swissvale, PA: the frost window
The last spring frost here typically falls around 04/18, about 233 days from today. Fall's first freeze usually shows up around 10/28, roughly 193 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 Swissvale, not a forecast for this year.
Stretching the season past the first frost
Swissvale'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.
Why 04/18 isn't a guarantee
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.
Swissvale against the rest of the dataset
At roughly 193 frost-free days, Swissvale places 19,822 of 40,283 ZIP codes in this dataset. Within PA, it ranks 419 of 2,088.
Learn more
Two guides worth reading on 15218: zone vs. frost date, on why Zone 6b and Swissvale's frost date answer different questions, and the frost range, on how to read the range around Swissvale's dates instead of trusting one.