Hartford, MI 49057 Frost Dates
49057, near Hartford, MI: the frost window
Around 04/22 is the usual last spring frost, about 237 days away. Fall's first freeze usually shows up around 10/30, roughly 189 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Hartford 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
Hartford's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/22 isn't a guarantee
04/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/07 and only about 1 year in 10 sees frost after that.
Hartford against the rest of the dataset
At roughly 189 frost-free days, Hartford places 21,598 of 40,283 ZIP codes in this dataset. Within MI, it ranks 43 of 1,153.
Learn more
Two guides worth reading on 49057: zone vs. frost date, on why Zone 6a and Hartford's frost date answer different questions, and the frost range, on how to read the range around Hartford's dates instead of trusting one.