Mount Morris, MI 48458 Frost Dates
48458, near Mount Morris, MI: the frost window
The last spring frost here typically falls around 05/08, about 253 days from today. Fall's first freeze usually shows up around 10/05, roughly 148 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Mount Morris in Zone 6a (-10 to -5°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
Mount Morris'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.
The actual range around Mount Morris's last frost
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/22 and only about 1 year in 10 sees frost after that.
Mount Morris against the rest of the dataset
Mount Morris's growing season runs about 148 days, ranking 35,720 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 838 of 1,153.
Learn more
Two guides worth reading on 48458: the frost range, on how to read the range around Mount Morris's dates instead of trusting one, and local microclimates, on what one yard in Mount Morris can differ from the 48458 normal.