Burtrum, MN 56318 Frost Dates
56318, near Burtrum, MN: the frost window
Around 05/13 is the usual last spring frost, about 258 days away. Fall's first freeze usually shows up around 09/27, roughly 134 days after the last spring frost.
Burtrum sits in USDA Zone 4b (-25 to -20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Burtrum'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 05/13 isn't a guarantee
05/13 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 05/28 and only about 1 year in 10 sees frost after that.
Burtrum against the rest of the dataset
About 134 days separate Burtrum's last and first frost, putting it 38,028 of 40,283 ZIP codes nationally. Within MN, it ranks 820 of 943.
Learn more
Two guides worth reading on 56318: local microclimates, on what one yard in Burtrum can differ from the 56318 normal, and zone vs. frost date, on why Zone 4b and Burtrum's frost date answer different questions.