Unionville, MI 48767 Frost Dates
48767, near Unionville, MI: the frost window
Typically, the last spring freeze lands around 05/07, roughly 252 days out. Fall's first freeze usually shows up around 10/09, roughly 154 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Unionville 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
Unionville's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/07 isn't a guarantee
05/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Unionville against the rest of the dataset
Unionville's growing season runs about 154 days, ranking 34,411 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 794 of 1,153.
Learn more
Two guides worth reading on 48767: local microclimates, on what one yard in Unionville can differ from the 48767 normal, and zone vs. frost date, on why Zone 6a and Unionville's frost date answer different questions.