Ellsworth, WI 54011 Frost Dates
54011, near Ellsworth, WI: the frost window
Typically, the last spring freeze lands around 05/13, roughly 258 days out. Fall's first freeze usually shows up around 09/29, roughly 139 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Ellsworth 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
Ellsworth's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/13 isn't a guarantee
05/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/27 and only about 1 year in 10 sees frost after that.
Ellsworth against the rest of the dataset
About 139 days separate Ellsworth's last and first frost, putting it 37,230 of 40,283 ZIP codes nationally. Within WI, it ranks 732 of 860.
Learn more
Two guides worth reading on 54011: zone vs. frost date, on why Zone 4b and Ellsworth's frost date answer different questions, and the frost range, on how to read the range around Ellsworth's dates instead of trusting one.