Boston, MA 02125 Frost Dates
Boston, MA: when does the frost end?
Around 04/19 is the usual last spring frost, about 234 days away. Fall's first freeze usually shows up around 10/23, roughly 185 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Boston in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 8 weeks until Boston's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Boston against the rest of the dataset
About 185 days separate Boston's last and first frost, putting it 23,000 of 40,283 ZIP codes nationally. Within MA, it ranks 166 of 712.
Learn more
Before leaning on 02125's figures: local microclimates explains what one yard in Boston can differ from the 02125 normal, while zone vs. frost date explains why Zone 7a and Boston's frost date answer different questions.