St. Clair, MI 48079 Frost Dates
48079, near St. Clair, MI: the frost window
Typically, the last spring freeze lands around 04/19, roughly 234 days out. Fall's first freeze usually shows up around 11/03, roughly 196 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts St. Clair 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
St. Clair's growing season runs out in roughly 10 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around St. Clair's last frost
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/04 and only about 1 year in 10 sees frost after that.
St. Clair against the rest of the dataset
St. Clair's growing season runs about 196 days, ranking 18,956 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 9 of 1,153.
Learn more
Two guides worth reading on 48079: the frost range, on how to read the range around St. Clair's dates instead of trusting one, and local microclimates, on what one yard in St. Clair can differ from the 48079 normal.