Grand Blanc, MI 48480 Frost Dates
Grand Blanc, MI: when does the frost end?
Around 05/01 is the usual last spring frost, about 246 days away. Fall's first freeze usually shows up around 10/14, roughly 164 days after the last spring frost.
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 Grand Blanc, not a forecast for this year.
Stretching the season past the first frost
With roughly 7 weeks until Grand Blanc's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/18 and only about 1 year in 10 sees frost after that.
Grand Blanc against the rest of the dataset
Grand Blanc's growing season runs about 164 days, ranking 30,892 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 479 of 1,153.
Learn more
Before leaning on 48480's figures: the frost range explains how to read the range around Grand Blanc's dates instead of trusting one, while local microclimates explains what one yard in Grand Blanc can differ from the 48480 normal.