Caribou, ME 04739 Frost Dates
When can you plant in Caribou, ME?
The last spring frost here typically falls around 05/23, about 268 days from today. The first fall frost typically arrives around 09/24, about 121 frost-free days later.
Caribou sits in USDA Zone 4a (-30 to -25°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.
What to do before the first frost
About 4 weeks of growing season left in Caribou before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/23 isn't a guarantee
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Caribou compares
At roughly 121 frost-free days, Caribou places 38,999 of 40,283 ZIP codes in this dataset. Within ME, it ranks 437 of 456.
Learn more
local microclimates covers what one yard in Caribou can differ from the 04739 normal. zone vs. frost date covers why Zone 4a and Caribou's frost date answer different questions.