Plymouth, WI 53073 Frost Dates
Frost dates for Plymouth, WI, ZIP 53073
The last spring frost here typically falls around 05/03, about 248 days from today. The first fall frost typically arrives around 10/10, about 159 frost-free days later.
Plymouth sits in USDA Zone 5b (-15 to -10°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 5b around Plymouth 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.
Why 05/03 isn't a guarantee
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/19 and you're betting against frost in roughly 9 years out of 10. 05/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Plymouth compares
At roughly 159 frost-free days, Plymouth places 32,629 of 40,283 ZIP codes in this dataset. Within WI, it ranks 350 of 860.
Learn more
local microclimates explains what one yard in Plymouth can differ from the 53073 normal, and zone vs. frost date explains why Zone 5b and Plymouth's frost date answer different questions.