Jefferson, PA 15346 Frost Dates
When can you plant in Jefferson, PA?
Around 05/03 is the usual last spring frost, about 248 days away. The first fall frost typically arrives around 10/15, about 164 frost-free days later.
The USDA Plant Hardiness Zone Map puts Jefferson in Zone 6b (-5 to 0°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 7 weeks of growing season left in Jefferson before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/03 isn't a guarantee
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/19 and you're betting against frost in roughly 9 years out of 10. 05/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Jefferson compares
Jefferson's growing season runs about 164 days, ranking 31,203 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,628 of 2,088.
Learn more
local microclimates covers what one yard in Jefferson can differ from the 15346 normal. zone vs. frost date covers why Zone 6b and Jefferson's frost date answer different questions.