Clontarf, MN 56226 Frost Dates
56226, near Clontarf, 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.
Zone 4b (-25 to -20°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Clontarf, not a forecast for this year.
Stretching the season past the first frost
Clontarf'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.
How much risk comes with planting early here
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.
Clontarf against the rest of the dataset
About 151 days separate Clontarf's last and first frost, putting it 35,191 of 40,283 ZIP codes nationally. Within MN, it ranks 503 of 943.
Learn more
Two guides worth reading on 56226: local microclimates, on what one yard in Clontarf can differ from the 56226 normal, and zone vs. frost date, on why Zone 4b and Clontarf's frost date answer different questions.