Dover, NH 03910 Frost Dates
03910, near Dover, NH: the frost window
Typically, the last spring freeze lands around 05/03, roughly 248 days out. Fall's first freeze usually shows up around 10/10, roughly 158 days after the last spring frost.
Zone 6a (-10 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 Dover, not a forecast for this year.
Stretching the season past the first frost
Dover's growing season runs out in roughly 6 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 Dover's last frost
05/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Dover against the rest of the dataset
At roughly 158 frost-free days, Dover places 32,898 of 40,283 ZIP codes in this dataset. Within NH, it ranks 77 of 260.
Learn more
Two guides worth reading on 03910: the frost range, on how to read the range around Dover's dates instead of trusting one, and local microclimates, on what one yard in Dover can differ from the 03910 normal.