Mackinaw City, MI 49718 Frost Dates
When can you plant in Mackinaw City, MI?
Around 05/21 is the usual last spring frost, about 266 days away. The first fall frost typically arrives around 09/27, about 128 frost-free days later.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Mackinaw City, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in Mackinaw City before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/21 is the middle of 30 years of NOAA records, not a promise. Plant by 05/04 and you're betting against frost in roughly 9 years out of 10. 06/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mackinaw City compares
About 128 days separate Mackinaw City's last and first frost, putting it 38,557 of 40,283 ZIP codes nationally. Within MI, it ranks 1,051 of 1,153.
Learn more
local microclimates covers what one yard in Mackinaw City can differ from the 49718 normal. zone vs. frost date covers why Zone 5b and Mackinaw City's frost date answer different questions.