FrostDateCheck

Belfast, ME 04627 Frost Dates

When can you plant in Belfast, ME?

Zone 6a

Typically, the last spring freeze lands around 05/07, roughly 252 days out. The first fall frost typically arrives around 10/05, about 151 frost-free days later.

Belfast sits in USDA Zone 6a (-10 to -5°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 5 weeks of growing season left in Belfast before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around Belfast's last frost

05/07 is the middle of 30 years of NOAA records, not a promise. Plant by 04/28 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 Belfast compares

Belfast's growing season runs about 151 days, ranking 34,985 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 257 of 456.

Learn more

local microclimates covers what one yard in Belfast can differ from the 04627 normal. zone vs. frost date covers why Zone 6a and Belfast's frost date answer different questions.