FrostDateCheck

Watertown, MA 02472 Frost Dates

When can you plant in Watertown, MA?

Zone 6b

The last spring frost here typically falls around 04/19, about 234 days from today. The first fall frost typically arrives around 10/23, about 185 frost-free days later.

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 Watertown, not a forecast for this year.

What to do before the first frost

About 8 weeks of growing season left in Watertown before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

The actual range around Watertown's last frost

04/19 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/03 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Watertown compares

About 185 days separate Watertown's last and first frost, putting it 23,064 of 40,283 ZIP codes nationally. Within MA, it ranks 195 of 712.

Learn more

the frost range covers how to read the range around Watertown's dates instead of trusting one. local microclimates covers what one yard in Watertown can differ from the 02472 normal.