Holly, MI 48442 Frost Dates
Frost dates for Holly, MI, ZIP 48442
Around 05/01 is the usual last spring frost, about 246 days away. The first fall frost typically arrives around 10/14, about 164 frost-free days later.
Zone 6a (-10 to -5°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 Holly, not a forecast for this year.
What to do before the first frost
Zone 6a around Holly 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.
Why 05/01 isn't a guarantee
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 Holly compares
At roughly 164 frost-free days, Holly places 30,906 of 40,283 ZIP codes in this dataset. Within MI, it ranks 482 of 1,153.
Learn more
zone vs. frost date explains why Zone 6a and Holly's frost date answer different questions, and the frost range explains how to read the range around Holly's dates instead of trusting one.