Hillsdale, MI 49242 Frost Dates
Hillsdale, MI: when does the frost end?
Typically, the last spring freeze lands around 05/03, roughly 248 days out. Fall's first freeze usually shows up around 10/12, roughly 161 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Hillsdale 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
With roughly 6 weeks until Hillsdale's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Hillsdale's last frost
05/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/19 and only about 1 year in 10 sees frost after that.
Hillsdale against the rest of the dataset
Hillsdale's growing season runs about 161 days, ranking 32,008 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 561 of 1,153.
Learn more
Before leaning on 49242's figures: local microclimates explains what one yard in Hillsdale can differ from the 49242 normal, while zone vs. frost date explains why Zone 6a and Hillsdale's frost date answer different questions.