Sister Bay, WI 54210 Frost Dates
54210, near Sister Bay, WI: the frost window
The last spring frost here typically falls around 05/14, about 259 days from today. Fall's first freeze usually shows up around 10/18, roughly 155 days after the last spring frost.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Sister Bay, not a forecast for this year.
Stretching the season past the first frost
Sister Bay's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/14 isn't a guarantee
05/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Sister Bay against the rest of the dataset
At roughly 155 frost-free days, Sister Bay places 34,035 of 40,283 ZIP codes in this dataset. Within WI, it ranks 441 of 860.
Learn more
Two guides worth reading on 54210: the frost range, on how to read the range around Sister Bay's dates instead of trusting one, and local microclimates, on what one yard in Sister Bay can differ from the 54210 normal.