Willmar, MN 56201 Frost Dates
56201, near Willmar, MN: the frost window
Typically, the last spring freeze lands around 04/30, roughly 245 days out. Fall's first freeze usually shows up around 10/07, roughly 159 days after the last spring frost.
Willmar sits in USDA Zone 4b (-25 to -20°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
Willmar's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Willmar's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Willmar against the rest of the dataset
At roughly 159 frost-free days, Willmar places 32,592 of 40,283 ZIP codes in this dataset. Within MN, it ranks 246 of 943.
Learn more
Two guides worth reading on 56201: local microclimates, on what one yard in Willmar can differ from the 56201 normal, and zone vs. frost date, on why Zone 4b and Willmar's frost date answer different questions.