East Grand Forks, MN 56721 Frost Dates
Frost dates for East Grand Forks, MN, ZIP 56721
Typically, the last spring freeze lands around 05/10, roughly 255 days out. The first fall frost typically arrives around 10/01, about 144 frost-free days later.
The USDA Plant Hardiness Zone Map puts East Grand Forks in Zone 4a (-30 to -25°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 4a around East Grand Forks 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.
Why 05/10 isn't a guarantee
05/10 is the middle of 30 years of NOAA records, not a promise. Plant by 04/28 and you're betting against frost in roughly 9 years out of 10. 05/24 is the safer bet, historically only a 1-in-10 chance of frost that late.
How East Grand Forks compares
East Grand Forks's growing season runs about 144 days, ranking 36,352 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 648 of 943.
Learn more
local microclimates explains what one yard in East Grand Forks can differ from the 56721 normal, and zone vs. frost date explains why Zone 4a and East Grand Forks's frost date answer different questions.