Royalton, MN 56373 Frost Dates
Royalton, MN: when does the frost end?
Around 05/10 is the usual last spring frost, about 255 days away. Fall's first freeze usually shows up around 09/29, roughly 140 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Royalton in Zone 4a (-30 to -25°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 5 weeks until Royalton's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/22 and only about 1 year in 10 sees frost after that.
Royalton against the rest of the dataset
At roughly 140 frost-free days, Royalton places 37,069 of 40,283 ZIP codes in this dataset. Within MN, it ranks 739 of 943.
Learn more
Before leaning on 56373's figures: zone vs. frost date explains why Zone 4a and Royalton's frost date answer different questions, while the frost range explains how to read the range around Royalton's dates instead of trusting one.