Ottertail, MN 56538 Frost Dates
Frost dates for Ottertail, MN, ZIP 56538
The last spring frost here typically falls around 05/05, about 250 days from today. The first fall frost typically arrives around 10/05, about 153 frost-free days later.
Ottertail 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 Ottertail 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.
The actual range around Ottertail's last frost
05/05 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. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Ottertail compares
At roughly 153 frost-free days, Ottertail places 34,580 of 40,283 ZIP codes in this dataset. Within MN, it ranks 421 of 943.
Learn more
the frost range explains how to read the range around Ottertail's dates instead of trusting one, and local microclimates explains what one yard in Ottertail can differ from the 56538 normal.