Bethlehem, PA 18017 Frost Dates
When can you plant in Bethlehem, PA?
Around 04/20 is the usual last spring frost, about 235 days away. The first fall frost typically arrives around 10/24, about 184 frost-free days later.
The USDA Plant Hardiness Zone Map puts Bethlehem in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 8 weeks of growing season left in Bethlehem before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/20 isn't a guarantee
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bethlehem compares
At roughly 184 frost-free days, Bethlehem places 23,398 of 40,283 ZIP codes in this dataset. Within PA, it ranks 755 of 2,088.
Learn more
zone vs. frost date covers why Zone 7a and Bethlehem's frost date answer different questions. the frost range covers how to read the range around Bethlehem's dates instead of trusting one.