Mendota Heights, MN 55120 Frost Dates
55120, near Mendota Heights, MN: the frost window
Typically, the last spring freeze lands around 04/25, roughly 240 days out. Fall's first freeze usually shows up around 10/12, roughly 169 days after the last spring frost.
Mendota Heights 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
Mendota Heights'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.
How much risk comes with planting early here
04/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/09 and only about 1 year in 10 sees frost after that.
Mendota Heights against the rest of the dataset
About 169 days separate Mendota Heights's last and first frost, putting it 29,375 of 40,283 ZIP codes nationally. Within MN, it ranks 89 of 943.
Learn more
Two guides worth reading on 55120: local microclimates, on what one yard in Mendota Heights can differ from the 55120 normal, and zone vs. frost date, on why Zone 5a and Mendota Heights's frost date answer different questions.