Port Jefferson, NY 11777 Frost Dates
Frost dates for Port Jefferson, NY, ZIP 11777
The last spring frost here typically falls around 04/04, about 219 days from today. 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
Zone 7b around Port Jefferson has about 10 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/04 isn't a guarantee
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
At roughly 215 frost-free days, Port Jefferson places 14,068 of 40,283 ZIP codes in this dataset. Within NY, it ranks 218 of 1,951.
Learn more
zone vs. frost date explains why Zone 7b and Port Jefferson's frost date answer different questions, and the frost range explains how to read the range around Port Jefferson's dates instead of trusting one.