Cohasset, MN 55721 Frost Dates
55721, near Cohasset, MN: the frost window
Around 05/16 is the usual last spring frost, about 261 days away. Fall's first freeze usually shows up around 10/01, roughly 138 days after the last spring frost.
Zone 4a (-30 to -25°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 Cohasset, not a forecast for this year.
Stretching the season past the first frost
Cohasset'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.
How much risk comes with planting early here
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Cohasset against the rest of the dataset
Cohasset's growing season runs about 138 days, ranking 37,392 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 768 of 943.
Learn more
Two guides worth reading on 55721: zone vs. frost date, on why Zone 4a and Cohasset's frost date answer different questions, and the frost range, on how to read the range around Cohasset's dates instead of trusting one.