Brookston, MN 55711 Frost Dates
55711, near Brookston, MN: the frost window
Typically, the last spring freeze lands around 05/29, roughly 274 days out. Fall's first freeze usually shows up around 09/18, roughly 111 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Brookston 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
Brookston's growing season runs out in roughly 3 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
05/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/13 and only about 1 year in 10 sees frost after that.
Brookston against the rest of the dataset
About 111 days separate Brookston's last and first frost, putting it 39,487 of 40,283 ZIP codes nationally. Within MN, it ranks 912 of 943.
Learn more
Two guides worth reading on 55711: the frost range, on how to read the range around Brookston's dates instead of trusting one, and local microclimates, on what one yard in Brookston can differ from the 55711 normal.