Manistique, MI 49817 Frost Dates
49817, near Manistique, MI: the frost window
Typically, the last spring freeze lands around 05/16, roughly 261 days out. Fall's first freeze usually shows up around 09/24, roughly 129 days after the last spring frost.
Manistique 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
Manistique's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/16 isn't a guarantee
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/03 and only about 1 year in 10 sees frost after that.
Manistique against the rest of the dataset
Manistique's growing season runs about 129 days, ranking 38,460 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 1,039 of 1,153.
Learn more
Two guides worth reading on 49817: local microclimates, on what one yard in Manistique can differ from the 49817 normal, and zone vs. frost date, on why Zone 5a and Manistique's frost date answer different questions.