Mellen, WI 54546 Frost Dates
Mellen, WI: when does the frost end?
Around 05/26 is the usual last spring frost, about 271 days away. Fall's first freeze usually shows up around 09/27, roughly 125 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Mellen in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 4 weeks until Mellen's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/26 isn't a guarantee
05/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/09 and only about 1 year in 10 sees frost after that.
Mellen against the rest of the dataset
At roughly 125 frost-free days, Mellen places 38,784 of 40,283 ZIP codes in this dataset. Within WI, it ranks 816 of 860.
Learn more
Before leaning on 54546's figures: local microclimates explains what one yard in Mellen can differ from the 54546 normal, while zone vs. frost date explains why Zone 4a and Mellen's frost date answer different questions.