Portage, MI 49081 Frost Dates
When can you plant in Portage, MI?
Around 04/29 is the usual last spring frost, about 244 days away. The first fall frost typically arrives around 10/20, about 173 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 Portage, not a forecast for this year.
What to do before the first frost
About 8 weeks of growing season left in Portage before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 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 Portage compares
At roughly 173 frost-free days, Portage places 27,771 of 40,283 ZIP codes in this dataset. Within MI, it ranks 203 of 1,153.
Learn more
the frost range covers how to read the range around Portage's dates instead of trusting one. local microclimates covers what one yard in Portage can differ from the 49081 normal.