Addison, MI 49220 Frost Dates
49220, near Addison, MI: the frost window
The last spring frost here typically falls around 05/05, about 250 days from today. Fall's first freeze usually shows up around 10/10, roughly 157 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Addison 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
Addison's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/05 isn't a guarantee
05/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/23 and only about 1 year in 10 sees frost after that.
Addison against the rest of the dataset
At roughly 157 frost-free days, Addison places 33,417 of 40,283 ZIP codes in this dataset. Within MI, it ranks 731 of 1,153.
Learn more
Two guides worth reading on 49220: local microclimates, on what one yard in Addison can differ from the 49220 normal, and zone vs. frost date, on why Zone 6a and Addison's frost date answer different questions.