Caribou, ME 04773 Frost Dates
Frost dates for Caribou, ME, ZIP 04773
The last spring frost here typically falls around 05/06, about 251 days from today. The first fall frost typically arrives around 10/02, about 147 frost-free days later.
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.
What to do before the first frost
Zone 4b around Caribou has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 05/06 isn't a guarantee
05/06 is the middle of 30 years of NOAA records, not a promise. Plant by 04/25 and you're betting against frost in roughly 9 years out of 10. 05/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Caribou compares
Caribou's growing season runs about 147 days, ranking 35,891 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 331 of 456.
Learn more
the frost range explains how to read the range around Caribou's dates instead of trusting one, and local microclimates explains what one yard in Caribou can differ from the 04773 normal.