Onamia, MN 56359 Frost Dates
When can you plant in Onamia, MN?
Typically, the last spring freeze lands around 05/10, roughly 255 days out. The first fall frost typically arrives around 10/03, about 144 frost-free days later.
Onamia 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
About 5 weeks of growing season left in Onamia before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/10 is the middle of 30 years of NOAA records, not a promise. Plant by 04/27 and you're betting against frost in roughly 9 years out of 10. 05/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Onamia compares
About 144 days separate Onamia's last and first frost, putting it 36,415 of 40,283 ZIP codes nationally. Within MN, it ranks 660 of 943.
Learn more
local microclimates covers what one yard in Onamia can differ from the 56359 normal. zone vs. frost date covers why Zone 4a and Onamia's frost date answer different questions.