Mason, MI 48924 Frost Dates
48924, near Mason, MI: the frost window
Around 04/28 is the usual last spring frost, about 243 days away. Fall's first freeze usually shows up around 10/17, roughly 173 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Mason 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
Mason's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/13 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Mason against the rest of the dataset
About 173 days separate Mason's last and first frost, putting it 27,828 of 40,283 ZIP codes nationally. Within MI, it ranks 219 of 1,153.
Learn more
Two guides worth reading on 48924: local microclimates, on what one yard in Mason can differ from the 48924 normal, and zone vs. frost date, on why Zone 6a and Mason's frost date answer different questions.