Iron Junction, MN 55766 Frost Dates
Iron Junction, MN: when does the frost end?
The last spring frost here typically falls around 05/27, about 272 days from today. Fall's first freeze usually shows up around 09/20, roughly 115 days after the last spring frost.
Iron Junction sits in USDA Zone 3b (-35 to -30°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.
Stretching the season past the first frost
With roughly 3 weeks until Iron Junction's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/11 and only about 1 year in 10 sees frost after that.
Iron Junction against the rest of the dataset
Iron Junction's growing season runs about 115 days, ranking 39,345 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 904 of 943.
Learn more
Before leaning on 55766's figures: the frost range explains how to read the range around Iron Junction's dates instead of trusting one, while local microclimates explains what one yard in Iron Junction can differ from the 55766 normal.