Dover, NH 03290 Frost Dates
Frost dates for Dover, NH, ZIP 03290
Around 05/07 is the usual last spring frost, about 252 days away. The first fall frost typically arrives around 10/04, about 148 frost-free days later.
The USDA Plant Hardiness Zone Map puts Dover in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 6a around Dover has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Dover's last frost
05/07 is the middle of 30 years of NOAA records, not a promise. Plant by 04/25 and you're betting against frost in roughly 9 years out of 10. 05/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Dover compares
At roughly 148 frost-free days, Dover places 35,624 of 40,283 ZIP codes in this dataset. Within NH, it ranks 134 of 260.
Learn more
the frost range explains how to read the range around Dover's dates instead of trusting one, and local microclimates explains what one yard in Dover can differ from the 03290 normal.