Middle River, MN 56737 Frost Dates
56737, near Middle River, MN: the frost window
Around 05/06 is the usual last spring frost, about 251 days away. Fall's first freeze usually shows up around 10/03, roughly 148 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Middle River 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
Middle River'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
05/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/20 and only about 1 year in 10 sees frost after that.
Middle River against the rest of the dataset
At roughly 148 frost-free days, Middle River places 35,797 of 40,283 ZIP codes in this dataset. Within MN, it ranks 598 of 943.
Learn more
Two guides worth reading on 56737: the frost range, on how to read the range around Middle River's dates instead of trusting one, and local microclimates, on what one yard in Middle River can differ from the 56737 normal.