Blackduck, MN 56630 Frost Dates
Blackduck, MN: when does the frost end?
Around 05/24 is the usual last spring frost, about 269 days away. Fall's first freeze usually shows up around 09/17, roughly 115 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Blackduck 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
With roughly 3 weeks until Blackduck's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/24 isn't a guarantee
05/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/06 and only about 1 year in 10 sees frost after that.
Blackduck against the rest of the dataset
Blackduck's growing season runs about 115 days, ranking 39,325 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 899 of 943.
Learn more
Before leaning on 56630's figures: local microclimates explains what one yard in Blackduck can differ from the 56630 normal, while zone vs. frost date explains why Zone 3b and Blackduck's frost date answer different questions.