Rose City, MI 48761 Frost Dates
Rose City, MI: when does the frost end?
Typically, the last spring freeze lands around 05/21, roughly 266 days out. Fall's first freeze usually shows up around 09/29, roughly 129 days after the last spring frost.
Zone 5a (-20 to -15°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 Rose City, not a forecast for this year.
Stretching the season past the first frost
With roughly 5 weeks until Rose City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/21 isn't a guarantee
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/05 and only about 1 year in 10 sees frost after that.
Rose City against the rest of the dataset
Rose City's growing season runs about 129 days, ranking 38,483 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 1,043 of 1,153.
Learn more
Before leaning on 48761's figures: local microclimates explains what one yard in Rose City can differ from the 48761 normal, while zone vs. frost date explains why Zone 5a and Rose City's frost date answer different questions.