Port Jefferson, NY 11727 Frost Dates
Port Jefferson, NY: when does the frost end?
Typically, the last spring freeze lands around 04/04, roughly 219 days out. Fall's first freeze usually shows up around 11/07, roughly 215 days after the last spring frost.
Port Jefferson sits in USDA Zone 7b (5 to 10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 10 weeks until Port Jefferson's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/04 isn't a guarantee
04/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/19 and only about 1 year in 10 sees frost after that.
Port Jefferson against the rest of the dataset
About 215 days separate Port Jefferson's last and first frost, putting it 14,064 of 40,283 ZIP codes nationally. Within NY, it ranks 214 of 1,951.
Learn more
Before leaning on 11727's figures: the frost range explains how to read the range around Port Jefferson's dates instead of trusting one, while local microclimates explains what one yard in Port Jefferson can differ from the 11727 normal.