Marlborough, MA 01853 Frost Dates
Marlborough, MA: when does the frost end?
Typically, the last spring freeze lands around 05/02, roughly 247 days out. Fall's first freeze usually shows up around 10/06, roughly 156 days after the last spring frost.
Marlborough 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.
Stretching the season past the first frost
With roughly 6 weeks until Marlborough's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/02 isn't a guarantee
05/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Marlborough against the rest of the dataset
Marlborough's growing season runs about 156 days, ranking 33,527 of 40,283 US ZIP codes measured here, longest to shortest. Within MA, it ranks 627 of 712.
Learn more
Before leaning on 01853's figures: zone vs. frost date explains why Zone 6b and Marlborough's frost date answer different questions, while the frost range explains how to read the range around Marlborough's dates instead of trusting one.