Belfast, ME 04850 Frost Dates
When can you plant in Belfast, ME?
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 5b (-15 to -10°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.
How much risk comes with planting early here
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 34,991 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 263 of 456.
Learn more
local microclimates covers what one yard in Belfast can differ from the 04850 normal. zone vs. frost date covers why Zone 5b and Belfast's frost date answer different questions.