Sault Ste. Marie, MI 49788 Frost Dates
49788, near Sault Ste. Marie, MI: the frost window
Typically, the last spring freeze lands around 06/01, roughly 277 days out. Fall's first freeze usually shows up around 09/21, roughly 110 days after the last spring frost.
Sault Ste. Marie sits in USDA Zone 5a (-20 to -15°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
Sault Ste. Marie's growing season runs out in roughly 3 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
06/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/20 and only about 1 year in 10 sees frost after that.
Sault Ste. Marie against the rest of the dataset
Sault Ste. Marie's growing season runs about 110 days, ranking 39,499 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 1,129 of 1,153.
Learn more
Two guides worth reading on 49788: the frost range, on how to read the range around Sault Ste. Marie's dates instead of trusting one, and local microclimates, on what one yard in Sault Ste. Marie can differ from the 49788 normal.