Sault Ste. Marie, MI 49724 Frost Dates
Sault Ste. Marie, MI: when does the frost end?
The last spring frost here typically falls around 05/22, about 267 days from today. Fall's first freeze usually shows up around 10/04, roughly 136 days after the last spring frost.
Zone 4b (-25 to -20°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 Sault Ste. Marie, not a forecast for this year.
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
About 136 days separate Sault Ste. Marie's last and first frost, putting it 37,649 of 40,283 ZIP codes nationally. Within MI, it ranks 946 of 1,153.
Learn more
Before leaning on 49724's figures: zone vs. frost date explains why Zone 4b and Sault Ste. Marie's frost date answer different questions, while the frost range explains how to read the range around Sault Ste. Marie's dates instead of trusting one.