Pontiac, MI 48340 Frost Dates
48340, near Pontiac, 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 10/20, roughly 172 days after the last spring frost.
Pontiac sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Pontiac'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.
How much risk comes with planting early here
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Pontiac against the rest of the dataset
Pontiac's growing season runs about 172 days, ranking 28,141 of 40,283 US ZIP codes measured here, longest to shortest. Within MI, it ranks 246 of 1,153.
Learn more
Two guides worth reading on 48340: the frost range, on how to read the range around Pontiac's dates instead of trusting one, and local microclimates, on what one yard in Pontiac can differ from the 48340 normal.