Whittemore, MI 48770 Frost Dates
Frost dates for Whittemore, MI, ZIP 48770
Around 05/23 is the usual last spring frost, about 268 days away. The first fall frost typically arrives around 09/26, about 127 frost-free days later.
Zone 5a (-20 to -15°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 Whittemore, not a forecast for this year.
What to do before the first frost
Zone 5a around Whittemore has about 4 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.
Why 05/23 isn't a guarantee
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/05 and you're betting against frost in roughly 9 years out of 10. 06/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Whittemore compares
At roughly 127 frost-free days, Whittemore places 38,653 of 40,283 ZIP codes in this dataset. Within MI, it ranks 1,066 of 1,153.
Learn more
local microclimates explains what one yard in Whittemore can differ from the 48770 normal, and zone vs. frost date explains why Zone 5a and Whittemore's frost date answer different questions.