Caribou, ME 04774 Frost Dates
04774, near Caribou, ME: the frost window
The last spring frost here typically falls around 06/02, about 278 days from today. Fall's first freeze usually shows up around 09/15, roughly 102 days after the last spring frost.
Caribou sits in USDA Zone 4b (-25 to -20°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
Caribou's growing season runs out in roughly 3 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 06/02 isn't a guarantee
06/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/21 and only about 1 year in 10 sees frost after that.
Caribou against the rest of the dataset
About 102 days separate Caribou's last and first frost, putting it 39,648 of 40,283 ZIP codes nationally. Within ME, it ranks 456 of 456.
Learn more
Two guides worth reading on 04774: local microclimates, on what one yard in Caribou can differ from the 04774 normal, and zone vs. frost date, on why Zone 4b and Caribou's frost date answer different questions.