Port Jefferson, NY 11766 Frost Dates
When can you plant in Port Jefferson, NY?
Typically, the last spring freeze lands around 04/04, roughly 219 days out. The first fall frost typically arrives around 11/07, about 215 frost-free days later.
The USDA Plant Hardiness Zone Map puts Port Jefferson in Zone 7b (5 to 10°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 10 weeks of growing season left in Port Jefferson before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/04 is the middle of 30 years of NOAA records, not a promise. Plant by 03/23 and you're betting against frost in roughly 9 years out of 10. 04/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Port Jefferson compares
About 215 days separate Port Jefferson's last and first frost, putting it 14,066 of 40,283 ZIP codes nationally. Within NY, it ranks 216 of 1,951.
Learn more
zone vs. frost date covers why Zone 7b and Port Jefferson's frost date answer different questions. the frost range covers how to read the range around Port Jefferson's dates instead of trusting one.