Manchester, NH 03057 Frost Dates
03057, near Manchester, NH: the frost window
Around 05/03 is the usual last spring frost, about 248 days away. Fall's first freeze usually shows up around 10/05, roughly 156 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Manchester in Zone 6a (-10 to -5°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
Manchester'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 05/03 isn't a guarantee
05/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Manchester against the rest of the dataset
At roughly 156 frost-free days, Manchester places 33,492 of 40,283 ZIP codes in this dataset. Within NH, it ranks 97 of 260.
Learn more
Two guides worth reading on 03057: zone vs. frost date, on why Zone 6a and Manchester's frost date answer different questions, and the frost range, on how to read the range around Manchester's dates instead of trusting one.