Waltham, MA 01742 Frost Dates
When can you plant in Waltham, MA?
The last spring frost here typically falls around 05/02, about 247 days from today. The first fall frost typically arrives around 10/06, about 156 frost-free days later.
Waltham 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.
What to do before the first frost
About 6 weeks of growing season left in Waltham before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/02 isn't a guarantee
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Waltham compares
About 156 days separate Waltham's last and first frost, putting it 33,504 of 40,283 ZIP codes nationally. Within MA, it ranks 604 of 712.
Learn more
local microclimates covers what one yard in Waltham can differ from the 01742 normal. zone vs. frost date covers why Zone 6b and Waltham's frost date answer different questions.