Clearbrook, MN 56634 Frost Dates
56634, near Clearbrook, MN: the frost window
Around 05/15 is the usual last spring frost, about 260 days away. Fall's first freeze usually shows up around 09/26, roughly 132 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Clearbrook in Zone 3b (-35 to -30°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
Clearbrook's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/30 and only about 1 year in 10 sees frost after that.
Clearbrook against the rest of the dataset
About 132 days separate Clearbrook's last and first frost, putting it 38,216 of 40,283 ZIP codes nationally. Within MN, it ranks 827 of 943.
Learn more
Two guides worth reading on 56634: zone vs. frost date, on why Zone 3b and Clearbrook's frost date answer different questions, and the frost range, on how to read the range around Clearbrook's dates instead of trusting one.