Port Jefferson, NY 11764 Frost Dates
Frost dates for Port Jefferson, NY, ZIP 11764
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.
Zone 7b (5 to 10°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 Port Jefferson, not a forecast for this year.
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.
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
Port Jefferson's growing season runs about 215 days, ranking 14,065 of 40,283 US ZIP codes measured here, longest to shortest. Within NY, it ranks 215 of 1,951.
Learn more
local microclimates explains what one yard in Port Jefferson can differ from the 11764 normal, and zone vs. frost date explains why Zone 7b and Port Jefferson's frost date answer different questions.