Caribou, ME 04756 Frost Dates
04756, near Caribou, ME: the frost window
The last spring frost here typically falls around 05/06, about 251 days from today. Fall's first freeze usually shows up around 10/02, roughly 147 days after the last spring frost.
Zone 4b (-25 to -20°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 Caribou, not a forecast for this year.
Stretching the season past the first frost
Caribou's growing season runs out in roughly 5 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
05/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/21 and only about 1 year in 10 sees frost after that.
Caribou against the rest of the dataset
About 147 days separate Caribou's last and first frost, putting it 35,889 of 40,283 ZIP codes nationally. Within ME, it ranks 329 of 456.
Learn more
Two guides worth reading on 04756: local microclimates, on what one yard in Caribou can differ from the 04756 normal, and zone vs. frost date, on why Zone 4b and Caribou's frost date answer different questions.