Princeton, NJ 08544 Frost Dates
08544, 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.
Zone 7a (0 to 5°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 Princeton, not a forecast for this year.
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.
How much risk comes with planting early here
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
Princeton's growing season runs about 173 days, ranking 27,789 of 40,283 US ZIP codes measured here, longest to shortest. Within NJ, it ranks 836 of 906.
Learn more
Two guides worth reading on 08544: zone vs. frost date, on why Zone 7a and Princeton's frost date answer different questions, and the frost range, on how to read the range around Princeton's dates instead of trusting one.