Ann Arbor, MI 48107 Frost Dates
Frost dates for Ann Arbor, MI, ZIP 48107
The last spring frost here typically falls around 05/08, about 253 days from today. The first fall frost typically arrives around 10/04, about 147 frost-free days later.
The USDA Plant Hardiness Zone Map puts Ann Arbor in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 6a around Ann Arbor has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/08 is the middle of 30 years of NOAA records, not a promise. Plant by 04/23 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Ann Arbor compares
At roughly 147 frost-free days, Ann Arbor places 35,825 of 40,283 ZIP codes in this dataset. Within MI, it ranks 855 of 1,153.
Learn more
local microclimates explains what one yard in Ann Arbor can differ from the 48107 normal, and zone vs. frost date explains why Zone 6a and Ann Arbor's frost date answer different questions.