Marlborough, MA 01866 Frost Dates
Marlborough, MA: when does the frost end?
The last spring frost here typically falls around 05/02, about 247 days from today. Fall's first freeze usually shows up around 10/06, roughly 156 days after the last spring frost.
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.
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.
The actual range around Marlborough's last frost
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 33,529 of 40,283 US ZIP codes measured here, longest to shortest. Within MA, it ranks 629 of 712.
Learn more
Before leaning on 01866'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.