Cambridge, MA 02446 Frost Dates
Frost dates for Cambridge, MA, ZIP 02446
Around 04/19 is the usual last spring frost, about 234 days away. The first fall frost typically arrives around 10/23, about 185 frost-free days later.
Cambridge sits in USDA Zone 6b (-5 to 0°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 6b around Cambridge has about 8 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 04/19 isn't a guarantee
04/19 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Cambridge compares
At roughly 185 frost-free days, Cambridge places 23,024 of 40,283 ZIP codes in this dataset. Within MA, it ranks 176 of 712.
Learn more
local microclimates explains what one yard in Cambridge can differ from the 02446 normal, and zone vs. frost date explains why Zone 6b and Cambridge's frost date answer different questions.