Belfast, ME 04987 Frost Dates
04987, near Belfast, ME: the frost window
The last spring frost here typically falls around 05/08, about 253 days from today. Fall's first freeze usually shows up around 10/03, roughly 148 days after the last spring frost.
Zone 5a (-20 to -15°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.
Stretching the season past the first frost
Belfast's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Belfast's last frost
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/23 and only about 1 year in 10 sees frost after that.
Belfast against the rest of the dataset
About 148 days separate Belfast's last and first frost, putting it 35,702 of 40,283 ZIP codes nationally. Within ME, it ranks 322 of 456.
Learn more
Two guides worth reading on 04987: the frost range, on how to read the range around Belfast's dates instead of trusting one, and local microclimates, on what one yard in Belfast can differ from the 04987 normal.