Rocky Hill, NJ 08528 Frost Dates
Rocky Hill, NJ: when does the frost end?
Around 04/25 is the usual last spring frost, about 240 days away. Fall's first freeze usually shows up around 10/16, roughly 173 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Rocky Hill in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 7 weeks until Rocky Hill's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/25 isn't a guarantee
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.
Rocky Hill against the rest of the dataset
About 173 days separate Rocky Hill's last and first frost, putting it 28,021 of 40,283 ZIP codes nationally. Within NJ, it ranks 855 of 906.
Learn more
Before leaning on 08528's figures: zone vs. frost date explains why Zone 7a and Rocky Hill's frost date answer different questions, while the frost range explains how to read the range around Rocky Hill's dates instead of trusting one.