Sister Bay, WI 54246 Frost Dates
Frost dates for Sister Bay, WI, ZIP 54246
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 10/14, about 152 frost-free days later.
Sister Bay sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 6a around Sister Bay has about 7 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Sister Bay compares
At roughly 152 frost-free days, Sister Bay places 34,800 of 40,283 ZIP codes in this dataset. Within WI, it ranks 522 of 860.
Learn more
the frost range explains how to read the range around Sister Bay's dates instead of trusting one, and local microclimates explains what one yard in Sister Bay can differ from the 54246 normal.