Somerville, MA 02222 Frost Dates
Frost dates for Somerville, MA, ZIP 02222
The last spring frost here typically falls around 04/04, about 219 days from today. The first fall frost typically arrives around 11/09, about 218 frost-free days later.
Somerville 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 Somerville 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.
Why 04/04 isn't a guarantee
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 Somerville compares
About 218 days separate Somerville's last and first frost, putting it 13,182 of 40,283 ZIP codes nationally. Within MA, it ranks 18 of 712.
Learn more
local microclimates explains what one yard in Somerville can differ from the 02222 normal, and zone vs. frost date explains why Zone 7a and Somerville's frost date answer different questions.