Marlborough, MA 01865 Frost Dates
When can you plant in Marlborough, MA?
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.
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.
Why 05/02 isn't a guarantee
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
About 156 days separate Marlborough's last and first frost, putting it 33,528 of 40,283 ZIP codes nationally. Within MA, it ranks 628 of 712.
Learn more
zone vs. frost date covers why Zone 6b and Marlborough's frost date answer different questions. the frost range covers how to read the range around Marlborough's dates instead of trusting one.