Groton, CT 06340 Frost Dates
Groton, CT: when does the frost end?
Typically, the last spring freeze lands around 04/08, roughly 223 days out. Fall's first freeze usually shows up around 11/02, roughly 207 days after the last spring frost.
Groton sits in USDA Zone 7a (0 to 5°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 9 weeks until Groton's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Groton's last frost
04/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/22 and only about 1 year in 10 sees frost after that.
Groton against the rest of the dataset
Groton's growing season runs about 207 days, ranking 15,809 of 40,283 US ZIP codes measured here, longest to shortest. Within CT, it ranks 28 of 391.
Learn more
Before leaning on 06340's figures: zone vs. frost date explains why Zone 7a and Groton's frost date answer different questions, while the frost range explains how to read the range around Groton's dates instead of trusting one.