Butterfield, MN 56120 Frost Dates
Butterfield, MN: when does the frost end?
Typically, the last spring freeze lands around 04/30, roughly 245 days out. Fall's first freeze usually shows up around 10/07, roughly 160 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Butterfield in Zone 5a (-20 to -15°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
With roughly 6 weeks until Butterfield's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Butterfield against the rest of the dataset
About 160 days separate Butterfield's last and first frost, putting it 32,475 of 40,283 ZIP codes nationally. Within MN, it ranks 226 of 943.
Learn more
Before leaning on 56120's figures: the frost range explains how to read the range around Butterfield's dates instead of trusting one, while local microclimates explains what one yard in Butterfield can differ from the 56120 normal.