Benson, MN 56215 Frost Dates
56215, near Benson, MN: the frost window
Typically, the last spring freeze lands around 05/04, roughly 249 days out. Fall's first freeze usually shows up around 10/03, roughly 151 days after the last spring frost.
Benson 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
Benson'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 05/04 isn't a guarantee
05/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/17 and only about 1 year in 10 sees frost after that.
Benson against the rest of the dataset
About 151 days separate Benson's last and first frost, putting it 35,023 of 40,283 ZIP codes nationally. Within MN, it ranks 489 of 943.
Learn more
Two guides worth reading on 56215: local microclimates, on what one yard in Benson can differ from the 56215 normal, and zone vs. frost date, on why Zone 4b and Benson's frost date answer different questions.