Stonington, CT 02812 Frost Dates
02812, near Stonington, CT: the frost window
Around 05/01 is the usual last spring frost, about 246 days away. Fall's first freeze usually shows up around 10/12, roughly 163 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Stonington 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
Stonington'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 05/01 isn't a guarantee
05/01 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 05/18 and only about 1 year in 10 sees frost after that.
Stonington against the rest of the dataset
About 163 days separate Stonington's last and first frost, putting it 31,458 of 40,283 ZIP codes nationally. Within CT, it ranks 356 of 391.
Learn more
Two guides worth reading on 02812: local microclimates, on what one yard in Stonington can differ from the 02812 normal, and zone vs. frost date, on why Zone 6b and Stonington's frost date answer different questions.