Saginaw, MI 48609 Frost Dates
48609, near Saginaw, MI: the frost window
Typically, the last spring freeze lands around 04/29, roughly 244 days out. Fall's first freeze usually shows up around 10/21, roughly 175 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 Saginaw, not a forecast for this year.
Stretching the season past the first frost
Saginaw's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Saginaw against the rest of the dataset
At roughly 175 frost-free days, Saginaw places 26,750 of 40,283 ZIP codes in this dataset. Within MI, it ranks 133 of 1,153.
Learn more
Two guides worth reading on 48609: zone vs. frost date, on why Zone 6a and Saginaw's frost date answer different questions, and the frost range, on how to read the range around Saginaw's dates instead of trusting one.