Caribou, ME 04736 Frost Dates
Caribou, ME: when does the frost end?
Around 05/07 is the usual last spring frost, about 252 days away. Fall's first freeze usually shows up around 10/01, roughly 143 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Caribou in Zone 4a (-30 to -25°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
With roughly 5 weeks until Caribou's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/07 isn't a guarantee
05/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/24 and only about 1 year in 10 sees frost after that.
Caribou against the rest of the dataset
About 143 days separate Caribou's last and first frost, putting it 36,516 of 40,283 ZIP codes nationally. Within ME, it ranks 349 of 456.
Learn more
Before leaning on 04736's figures: local microclimates explains what one yard in Caribou can differ from the 04736 normal, while zone vs. frost date explains why Zone 4a and Caribou's frost date answer different questions.