FrostDateCheck

Belfast, ME 04421 Frost Dates

When can you plant in Belfast, ME?

Zone 5b

The last spring frost here typically falls around 05/07, about 252 days from today. The first fall frost typically arrives around 10/05, about 151 frost-free days later.

Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Belfast, not a forecast for this year.

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

At roughly 151 frost-free days, Belfast places 34,982 of 40,283 ZIP codes in this dataset. Within ME, it ranks 254 of 456.

Learn more

the frost range covers how to read the range around Belfast's dates instead of trusting one. local microclimates covers what one yard in Belfast can differ from the 04421 normal.