Bloomington, MN 55420 Frost Dates
Bloomington, MN: when does the frost end?
Typically, the last spring freeze lands around 04/23, roughly 238 days out. Fall's first freeze usually shows up around 10/18, roughly 176 days after the last spring frost.
Bloomington 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
With roughly 7 weeks until Bloomington's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/23 isn't a guarantee
04/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/07 and only about 1 year in 10 sees frost after that.
Bloomington against the rest of the dataset
Bloomington's growing season runs about 176 days, ranking 26,336 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 25 of 943.
Learn more
Before leaning on 55420's figures: zone vs. frost date explains why Zone 5a and Bloomington's frost date answer different questions, while the frost range explains how to read the range around Bloomington's dates instead of trusting one.