Flint, MI 48551 Frost Dates
Frost dates for Flint, MI, ZIP 48551
Around 05/06 is the usual last spring frost, about 251 days away. The first fall frost typically arrives around 10/10, about 155 frost-free days later.
The USDA Plant Hardiness Zone Map puts Flint 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 Flint has about 6 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 05/06 isn't a guarantee
05/06 is the middle of 30 years of NOAA records, not a promise. Plant by 04/21 and you're betting against frost in roughly 9 years out of 10. 05/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Flint compares
At roughly 155 frost-free days, Flint places 33,905 of 40,283 ZIP codes in this dataset. Within MI, it ranks 769 of 1,153.
Learn more
zone vs. frost date explains why Zone 6a and Flint's frost date answer different questions, and the frost range explains how to read the range around Flint's dates instead of trusting one.