Ortonville, MI 48462 Frost Dates
Frost dates for Ortonville, MI, ZIP 48462
Typically, the last spring freeze lands around 05/01, roughly 246 days out. The first fall frost typically arrives around 10/14, about 164 frost-free days later.
The USDA Plant Hardiness Zone Map puts Ortonville 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 Ortonville has about 7 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
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/20 and you're betting against frost in roughly 9 years out of 10. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Ortonville compares
At roughly 164 frost-free days, Ortonville places 31,030 of 40,283 ZIP codes in this dataset. Within MI, it ranks 493 of 1,153.
Learn more
local microclimates explains what one yard in Ortonville can differ from the 48462 normal, and zone vs. frost date explains why Zone 6a and Ortonville's frost date answer different questions.