Leominster, MA 01523 Frost Dates
01523, near Leominster, MA: the frost window
The last spring frost here typically falls around 04/29, about 244 days from today. Fall's first freeze usually shows up around 10/11, roughly 164 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 Leominster, not a forecast for this year.
Stretching the season past the first frost
Leominster's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Leominster against the rest of the dataset
About 164 days separate Leominster's last and first frost, putting it 30,841 of 40,283 ZIP codes nationally. Within MA, it ranks 427 of 712.
Learn more
Two guides worth reading on 01523: local microclimates, on what one yard in Leominster can differ from the 01523 normal, and zone vs. frost date, on why Zone 6b and Leominster's frost date answer different questions.