FrostDateCheck

Marlborough, MA 01772 Frost Dates

Marlborough, MA: when does the frost end?

Zone 6b

Typically, the last spring freeze lands around 04/26, roughly 241 days out. Fall's first freeze usually shows up around 10/12, roughly 169 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.

Why 04/26 isn't a guarantee

04/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/09 and only about 1 year in 10 sees frost after that.

Marlborough against the rest of the dataset

At roughly 169 frost-free days, Marlborough places 29,326 of 40,283 ZIP codes in this dataset. Within MA, it ranks 350 of 712.

Learn more

Before leaning on 01772's figures: local microclimates explains what one yard in Marlborough can differ from the 01772 normal, while zone vs. frost date explains why Zone 6b and Marlborough's frost date answer different questions.