DeForest, WI 53598 Frost Dates
Frost dates for DeForest, WI, ZIP 53598
Typically, the last spring freeze lands around 05/01, roughly 246 days out. The first fall frost typically arrives around 10/10, about 160 frost-free days later.
DeForest sits in USDA Zone 5a (-20 to -15°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 5a around DeForest 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 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/16 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How DeForest compares
DeForest's growing season runs about 160 days, ranking 32,262 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 337 of 860.
Learn more
zone vs. frost date explains why Zone 5a and DeForest's frost date answer different questions, and the frost range explains how to read the range around DeForest's dates instead of trusting one.