Harbor Springs, MI 49740 Frost Dates
Harbor Springs, MI: when does the frost end?
The last spring frost here typically falls around 05/06, about 251 days from today. Fall's first freeze usually shows up around 10/20, roughly 166 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Harbor Springs in Zone 5b (-15 to -10°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
With roughly 8 weeks until Harbor Springs's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/06 isn't a guarantee
05/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/21 and only about 1 year in 10 sees frost after that.
Harbor Springs against the rest of the dataset
Harbor Springs's growing season runs about 166 days, ranking 30,404 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 421 of 1,153.
Learn more
Before leaning on 49740's figures: the frost range explains how to read the range around Harbor Springs's dates instead of trusting one, while local microclimates explains what one yard in Harbor Springs can differ from the 49740 normal.