FrostDateCheck

Marlborough, MA 01740 Frost Dates

When can you plant in Marlborough, MA?

Zone 6b

The last spring frost here typically falls around 05/02, about 247 days from today. The first fall frost typically arrives around 10/06, about 156 frost-free days later.

The USDA Plant Hardiness Zone Map puts Marlborough in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.

What to do before the first frost

About 6 weeks of growing season left in Marlborough before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

How much risk comes with planting early here

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

At roughly 156 frost-free days, Marlborough places 33,517 of 40,283 ZIP codes in this dataset. Within MA, it ranks 617 of 712.

Learn more

local microclimates covers what one yard in Marlborough can differ from the 01740 normal. zone vs. frost date covers why Zone 6b and Marlborough's frost date answer different questions.