Marlborough, MA 01813 Frost Dates
Marlborough, MA: when does the frost end?
Around 05/02 is the usual last spring frost, about 247 days away. Fall's first freeze usually shows up around 10/06, roughly 156 days after the last spring frost.
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.
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.
How much risk comes with planting early here
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 33,524 of 40,283 US ZIP codes measured here, longest to shortest. Within MA, it ranks 624 of 712.
Learn more
Before leaning on 01813'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.