Markesan, WI 53946 Frost Dates
53946, near Markesan, WI: the frost window
Typically, the last spring freeze lands around 05/08, roughly 253 days out. Fall's first freeze usually shows up around 10/02, roughly 144 days after the last spring frost.
Markesan 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.
Stretching the season past the first frost
Markesan's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/08 isn't a guarantee
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/23 and only about 1 year in 10 sees frost after that.
Markesan against the rest of the dataset
Markesan's growing season runs about 144 days, ranking 36,397 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 671 of 860.
Learn more
Two guides worth reading on 53946: local microclimates, on what one yard in Markesan can differ from the 53946 normal, and zone vs. frost date, on why Zone 5a and Markesan's frost date answer different questions.