Marlborough, MA 02475 Frost Dates
Frost dates for Marlborough, MA, ZIP 02475
Typically, the last spring freeze lands around 05/02, roughly 247 days out. The first fall frost typically arrives around 10/06, about 156 frost-free days later.
Zone 6b (-5 to 0°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 Marlborough, not a forecast for this year.
What to do before the first frost
Zone 6b around Marlborough has about 6 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 Marlborough's last frost
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Marlborough compares
Marlborough's growing season runs about 156 days, ranking 33,536 of 40,283 US ZIP codes measured here, longest to shortest. Within MA, it ranks 636 of 712.
Learn more
local microclimates explains what one yard in Marlborough can differ from the 02475 normal, and zone vs. frost date explains why Zone 6b and Marlborough's frost date answer different questions.