Rochester, NH 03851 Frost Dates
Frost dates for Rochester, NH, ZIP 03851
The last spring frost here typically falls around 04/30, about 245 days from today. The first fall frost typically arrives around 10/09, about 161 frost-free days later.
Rochester sits in USDA Zone 5b (-15 to -10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 5b around Rochester has about 6 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.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/18 and you're betting against frost in roughly 9 years out of 10. 05/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rochester compares
About 161 days separate Rochester's last and first frost, putting it 31,958 of 40,283 ZIP codes nationally. Within NH, it ranks 60 of 260.
Learn more
local microclimates explains what one yard in Rochester can differ from the 03851 normal, and zone vs. frost date explains why Zone 5b and Rochester's frost date answer different questions.