Grand Marais, MN 55606 Frost Dates
55606, near Grand Marais, MN: the frost window
Around 05/24 is the usual last spring frost, about 269 days away. Fall's first freeze usually shows up around 09/29, roughly 127 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Grand Marais in Zone 4a (-30 to -25°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
Grand Marais'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.
The actual range around Grand Marais's last frost
05/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/05 and only about 1 year in 10 sees frost after that.
Grand Marais against the rest of the dataset
Grand Marais's growing season runs about 127 days, ranking 38,637 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 876 of 943.
Learn more
Two guides worth reading on 55606: zone vs. frost date, on why Zone 4a and Grand Marais's frost date answer different questions, and the frost range, on how to read the range around Grand Marais's dates instead of trusting one.