Duluth, MN 55805 Frost Dates
When can you plant in Duluth, MN?
Typically, the last spring freeze lands around 05/14, roughly 259 days out. The first fall frost typically arrives around 10/12, about 149 frost-free days later.
Duluth sits in USDA Zone 4b (-25 to -20°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 6 weeks of growing season left in Duluth before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Duluth's last frost
05/14 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Duluth compares
About 149 days separate Duluth's last and first frost, putting it 35,474 of 40,283 ZIP codes nationally. Within MN, it ranks 559 of 943.
Learn more
local microclimates covers what one yard in Duluth can differ from the 55805 normal. zone vs. frost date covers why Zone 4b and Duluth's frost date answer different questions.