Harrisville, MI 48738 Frost Dates
48738, near Harrisville, 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 10/16, roughly 160 days after the last spring frost.
Zone 6a (-10 to -5°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 Harrisville, not a forecast for this year.
Stretching the season past the first frost
Harrisville's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/26 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Harrisville against the rest of the dataset
At roughly 160 frost-free days, Harrisville places 32,490 of 40,283 ZIP codes in this dataset. Within MI, it ranks 643 of 1,153.
Learn more
Two guides worth reading on 48738: zone vs. frost date, on why Zone 6a and Harrisville's frost date answer different questions, and the frost range, on how to read the range around Harrisville's dates instead of trusting one.