Rochester, MN 55902 Frost Dates
55902, near Rochester, MN: the frost window
Around 04/30 is the usual last spring frost, about 245 days away. Fall's first freeze usually shows up around 10/06, roughly 159 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Rochester in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Rochester'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
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 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.
Rochester against the rest of the dataset
At roughly 159 frost-free days, Rochester places 32,566 of 40,283 ZIP codes in this dataset. Within MN, it ranks 236 of 943.
Learn more
Two guides worth reading on 55902: zone vs. frost date, on why Zone 4b and Rochester's frost date answer different questions, and the frost range, on how to read the range around Rochester's dates instead of trusting one.