Boston, MA 02108 Frost Dates
Frost dates for Boston, MA, ZIP 02108
Typically, the last spring freeze lands around 04/04, roughly 219 days out. The first fall frost typically arrives around 11/09, about 218 frost-free days later.
Boston sits in USDA Zone 7a (0 to 5°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 7a around Boston has about 10 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.
The actual range around Boston's last frost
04/04 is the middle of 30 years of NOAA records, not a promise. Plant by 03/25 and you're betting against frost in roughly 9 years out of 10. 04/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Boston compares
At roughly 218 frost-free days, Boston places 13,134 of 40,283 ZIP codes in this dataset. Within MA, it ranks 1 of 712.
Learn more
local microclimates explains what one yard in Boston can differ from the 02108 normal, and zone vs. frost date explains why Zone 7a and Boston's frost date answer different questions.