Princeton, NJ 08540 Frost Dates
08540, near Princeton, NJ: the frost window
Typically, the last spring freeze lands around 04/25, roughly 240 days out. Fall's first freeze usually shows up around 10/16, roughly 173 days after the last spring frost.
Princeton sits in USDA Zone 7a (0 to 5°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
Princeton's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Princeton's last frost
04/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/12 and only about 1 year in 10 sees frost after that.
Princeton against the rest of the dataset
About 173 days separate Princeton's last and first frost, putting it 27,787 of 40,283 ZIP codes nationally. Within NJ, it ranks 834 of 906.
Learn more
Two guides worth reading on 08540: the frost range, on how to read the range around Princeton's dates instead of trusting one, and local microclimates, on what one yard in Princeton can differ from the 08540 normal.