Platteville, WI 53818 Frost Dates
Platteville, WI: when does the frost end?
Around 04/30 is the usual last spring frost, about 245 days away. Fall's first freeze usually shows up around 10/13, roughly 166 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Platteville in Zone 5a (-20 to -15°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 7 weeks until Platteville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Platteville against the rest of the dataset
About 166 days separate Platteville's last and first frost, putting it 30,311 of 40,283 ZIP codes nationally. Within WI, it ranks 172 of 860.
Learn more
Before leaning on 53818's figures: local microclimates explains what one yard in Platteville can differ from the 53818 normal, while zone vs. frost date explains why Zone 5a and Platteville's frost date answer different questions.