Rochester, NH 03261 Frost Dates
03261, near Rochester, NH: the frost window
Typically, the last spring freeze lands around 05/08, roughly 253 days out. Fall's first freeze usually shows up around 10/04, roughly 148 days after the last spring frost.
Rochester sits in USDA Zone 6a (-10 to -5°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.
Stretching the season past the first frost
Rochester's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/08 isn't a guarantee
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/22 and only about 1 year in 10 sees frost after that.
Rochester against the rest of the dataset
Rochester's growing season runs about 148 days, ranking 35,626 of 40,283 US ZIP codes measured here, longest to shortest. Within NH, it ranks 136 of 260.
Learn more
Two guides worth reading on 03261: the frost range, on how to read the range around Rochester's dates instead of trusting one, and local microclimates, on what one yard in Rochester can differ from the 03261 normal.