Bigfork, MN 56657 Frost Dates
Frost dates for Bigfork, MN, ZIP 56657
The last spring frost here typically falls around 05/14, about 259 days from today. The first fall frost typically arrives around 10/02, about 140 frost-free days later.
Zone 3b (-35 to -30°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 Bigfork, not a forecast for this year.
What to do before the first frost
Zone 3b around Bigfork has about 5 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.
How much risk comes with planting early here
05/14 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bigfork compares
Bigfork's growing season runs about 140 days, ranking 37,138 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 746 of 943.
Learn more
the frost range explains how to read the range around Bigfork's dates instead of trusting one, and local microclimates explains what one yard in Bigfork can differ from the 56657 normal.