Clearwater, MN 55320 Frost Dates
When can you plant in Clearwater, MN?
Typically, the last spring freeze lands around 05/07, roughly 252 days out. The first fall frost typically arrives around 09/30, about 144 frost-free days later.
Clearwater 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 5 weeks of growing season left in Clearwater before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/07 isn't a guarantee
05/07 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. 05/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Clearwater compares
Clearwater's growing season runs about 144 days, ranking 36,373 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 655 of 943.
Learn more
local microclimates covers what one yard in Clearwater can differ from the 55320 normal. zone vs. frost date covers why Zone 4b and Clearwater's frost date answer different questions.