Franklin, NH 03287 Frost Dates
03287, near Franklin, NH: the frost window
Around 05/21 is the usual last spring frost, about 266 days away. Fall's first freeze usually shows up around 09/26, roughly 127 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Franklin in Zone 5b (-15 to -10°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
Franklin's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/21 isn't a guarantee
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/05 and only about 1 year in 10 sees frost after that.
Franklin against the rest of the dataset
About 127 days separate Franklin's last and first frost, putting it 38,617 of 40,283 ZIP codes nationally. Within NH, it ranks 253 of 260.
Learn more
Two guides worth reading on 03287: zone vs. frost date, on why Zone 5b and Franklin's frost date answer different questions, and the frost range, on how to read the range around Franklin's dates instead of trusting one.