Bath, ME 04558 Frost Dates
04558, near Bath, ME: the frost window
The last spring frost here typically falls around 04/28, about 243 days from today. Fall's first freeze usually shows up around 10/21, roughly 175 days after the last spring frost.
Zone 6a (-10 to -5°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 Bath, not a forecast for this year.
Stretching the season past the first frost
Bath's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/28 isn't a guarantee
04/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/09 and only about 1 year in 10 sees frost after that.
Bath against the rest of the dataset
About 175 days separate Bath's last and first frost, putting it 26,833 of 40,283 ZIP codes nationally. Within ME, it ranks 57 of 456.
Learn more
Two guides worth reading on 04558: local microclimates, on what one yard in Bath can differ from the 04558 normal, and zone vs. frost date, on why Zone 6a and Bath's frost date answer different questions.