Plainfield, WI 54921 Frost Dates
Plainfield, WI: when does the frost end?
Around 05/10 is the usual last spring frost, about 255 days away. Fall's first freeze usually shows up around 10/03, roughly 146 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Plainfield in Zone 4b (-25 to -20°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 5 weeks until Plainfield's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Plainfield's last frost
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Plainfield against the rest of the dataset
At roughly 146 frost-free days, Plainfield places 36,072 of 40,283 ZIP codes in this dataset. Within WI, it ranks 643 of 860.
Learn more
Before leaning on 54921's figures: local microclimates explains what one yard in Plainfield can differ from the 54921 normal, while zone vs. frost date explains why Zone 4b and Plainfield's frost date answer different questions.