Waltham, MA 02454 Frost Dates
Waltham, MA: when does the frost end?
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.
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.
Stretching the season past the first frost
With roughly 6 weeks until Waltham'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.
Waltham against the rest of the dataset
About 169 days separate Waltham's last and first frost, putting it 29,309 of 40,283 ZIP codes nationally. Within MA, it ranks 346 of 712.
Learn more
Before leaning on 02454's figures: zone vs. frost date explains why Zone 6b and Waltham's frost date answer different questions, while the frost range explains how to read the range around Waltham's dates instead of trusting one.