Sault Ste. Marie, MI 49715 Frost Dates
Sault Ste. Marie, MI: when does the frost end?
Typically, the last spring freeze lands around 05/22, roughly 267 days out. Fall's first freeze usually shows up around 10/04, roughly 136 days after the last spring frost.
Sault Ste. Marie 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
With roughly 5 weeks until Sault Ste. Marie's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/22 isn't a guarantee
05/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/04 and only about 1 year in 10 sees frost after that.
Sault Ste. Marie against the rest of the dataset
At roughly 136 frost-free days, Sault Ste. Marie places 37,648 of 40,283 ZIP codes in this dataset. Within MI, it ranks 945 of 1,153.
Learn more
Before leaning on 49715's figures: the frost range explains how to read the range around Sault Ste. Marie's dates instead of trusting one, while local microclimates explains what one yard in Sault Ste. Marie can differ from the 49715 normal.