Prairie du Sac, WI 53578 Frost Dates
Frost dates for Prairie du Sac, WI, ZIP 53578
The last spring frost here typically falls around 05/04, about 249 days from today. The first fall frost typically arrives around 10/06, about 155 frost-free days later.
The USDA Plant Hardiness Zone Map puts Prairie du Sac in Zone 5a (-20 to -15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 5a around Prairie du Sac has about 6 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
05/04 is the middle of 30 years of NOAA records, not a promise. Plant by 04/20 and you're betting against frost in roughly 9 years out of 10. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Prairie du Sac compares
At roughly 155 frost-free days, Prairie du Sac places 33,964 of 40,283 ZIP codes in this dataset. Within WI, it ranks 437 of 860.
Learn more
zone vs. frost date explains why Zone 5a and Prairie du Sac's frost date answer different questions, and the frost range explains how to read the range around Prairie du Sac's dates instead of trusting one.