Hersey, MI 49639 Frost Dates
49639, near Hersey, MI: the frost window
Typically, the last spring freeze lands around 05/13, roughly 258 days out. Fall's first freeze usually shows up around 10/02, roughly 142 days after the last spring frost.
Hersey 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
Hersey's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/13 isn't a guarantee
05/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Hersey against the rest of the dataset
At roughly 142 frost-free days, Hersey places 36,809 of 40,283 ZIP codes in this dataset. Within MI, it ranks 903 of 1,153.
Learn more
Two guides worth reading on 49639: local microclimates, on what one yard in Hersey can differ from the 49639 normal, and zone vs. frost date, on why Zone 5a and Hersey's frost date answer different questions.