Belfast, ME 04438 Frost Dates
Frost dates for Belfast, ME, ZIP 04438
Typically, the last spring freeze lands around 05/04, roughly 249 days out. The first fall frost typically arrives around 10/04, about 152 frost-free days later.
Belfast sits in USDA Zone 5a (-20 to -15°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 5a around Belfast 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.
How much risk comes with planting early here
05/04 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Belfast compares
About 152 days separate Belfast's last and first frost, putting it 34,739 of 40,283 ZIP codes nationally. Within ME, it ranks 241 of 456.
Learn more
the frost range explains how to read the range around Belfast's dates instead of trusting one, and local microclimates explains what one yard in Belfast can differ from the 04438 normal.