Barnum, MN 55707 Frost Dates
Frost dates for Barnum, MN, ZIP 55707
Around 05/12 is the usual last spring frost, about 257 days away. The first fall frost typically arrives around 10/02, about 144 frost-free days later.
Barnum sits in USDA Zone 4a (-30 to -25°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 4a around Barnum 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 05/12 isn't a guarantee
05/12 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. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Barnum compares
About 144 days separate Barnum's last and first frost, putting it 36,429 of 40,283 ZIP codes nationally. Within MN, it ranks 663 of 943.
Learn more
local microclimates explains what one yard in Barnum can differ from the 55707 normal, and zone vs. frost date explains why Zone 4a and Barnum's frost date answer different questions.