Williams Bay, WI 53191 Frost Dates
Frost dates for Williams Bay, WI, ZIP 53191
The last spring frost here typically falls around 04/25, about 240 days from today. The first fall frost typically arrives around 10/21, about 179 frost-free days later.
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 Williams Bay, not a forecast for this year.
What to do before the first frost
Zone 5b around Williams Bay has about 8 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
04/25 is the middle of 30 years of NOAA records, not a promise. Plant by 04/10 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williams Bay compares
About 179 days separate Williams Bay's last and first frost, putting it 25,309 of 40,283 ZIP codes nationally. Within WI, it ranks 38 of 860.
Learn more
local microclimates explains what one yard in Williams Bay can differ from the 53191 normal, and zone vs. frost date explains why Zone 5b and Williams Bay's frost date answer different questions.