Crystal Falls, MI 49920 Frost Dates
Crystal Falls, MI: when does the frost end?
Typically, the last spring freeze lands around 06/06, roughly 282 days out. Fall's first freeze usually shows up around 09/09, roughly 94 days after the last spring frost.
Zone 4a (-30 to -25°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 Crystal Falls, not a forecast for this year.
Stretching the season past the first frost
With roughly 2 weeks until Crystal Falls's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 06/06 isn't a guarantee
06/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 07/07 and only about 1 year in 10 sees frost after that.
Crystal Falls against the rest of the dataset
At roughly 94 frost-free days, Crystal Falls places 39,834 of 40,283 ZIP codes in this dataset. Within MI, it ranks 1,151 of 1,153.
Learn more
Before leaning on 49920's figures: zone vs. frost date explains why Zone 4a and Crystal Falls's frost date answer different questions, while the frost range explains how to read the range around Crystal Falls's dates instead of trusting one.