South Bethlehem, PA 16223 Frost Dates
16223, near South Bethlehem, PA: the frost window
Typically, the last spring freeze lands around 05/10, roughly 255 days out. Fall's first freeze usually shows up around 10/12, roughly 155 days after the last spring frost.
Zone 6a (-10 to -5°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 South Bethlehem, not a forecast for this year.
Stretching the season past the first frost
South Bethlehem's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around South Bethlehem's last frost
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
South Bethlehem against the rest of the dataset
At roughly 155 frost-free days, South Bethlehem places 34,082 of 40,283 ZIP codes in this dataset. Within PA, it ranks 1,812 of 2,088.
Learn more
Two guides worth reading on 16223: local microclimates, on what one yard in South Bethlehem can differ from the 16223 normal, and zone vs. frost date, on why Zone 6a and South Bethlehem's frost date answer different questions.