Woburn, MA 01821 Frost Dates
01821, near Woburn, MA: the frost window
Around 04/27 is the usual last spring frost, about 242 days away. Fall's first freeze usually shows up around 10/13, roughly 169 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Woburn 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
Woburn's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/13 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/11 and only about 1 year in 10 sees frost after that.
Woburn against the rest of the dataset
At roughly 169 frost-free days, Woburn places 29,325 of 40,283 ZIP codes in this dataset. Within MA, it ranks 349 of 712.
Learn more
Two guides worth reading on 01821: local microclimates, on what one yard in Woburn can differ from the 01821 normal, and zone vs. frost date, on why Zone 6b and Woburn's frost date answer different questions.