Blaine, MN 55449 Frost Dates
Blaine, MN: when does the frost end?
Around 05/05 is the usual last spring frost, about 250 days away. Fall's first freeze usually shows up around 10/02, roughly 148 days after the last spring frost.
Zone 5a (-20 to -15°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Blaine, not a forecast for this year.
Stretching the season past the first frost
With roughly 5 weeks until Blaine's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/05 isn't a guarantee
05/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/21 and only about 1 year in 10 sees frost after that.
Blaine against the rest of the dataset
At roughly 148 frost-free days, Blaine places 35,614 of 40,283 ZIP codes in this dataset. Within MN, it ranks 575 of 943.
Learn more
Before leaning on 55449's figures: the frost range explains how to read the range around Blaine's dates instead of trusting one, while local microclimates explains what one yard in Blaine can differ from the 55449 normal.