Port Austin, MI 48467 Frost Dates
48467, near Port Austin, MI: the frost window
Around 05/04 is the usual last spring frost, about 249 days away. Fall's first freeze usually shows up around 10/26, roughly 172 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Port Austin in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Port Austin's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/04 isn't a guarantee
05/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/19 and only about 1 year in 10 sees frost after that.
Port Austin against the rest of the dataset
Port Austin's growing season runs about 172 days, ranking 28,430 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 271 of 1,153.
Learn more
Two guides worth reading on 48467: zone vs. frost date, on why Zone 6a and Port Austin's frost date answer different questions, and the frost range, on how to read the range around Port Austin's dates instead of trusting one.