Newtown, CT 06488 Frost Dates
06488, near Newtown, CT: the frost window
The last spring frost here typically falls around 04/20, about 235 days from today. Fall's first freeze usually shows up around 10/20, roughly 181 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Newtown 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
Newtown's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/20 isn't a guarantee
04/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Newtown against the rest of the dataset
About 181 days separate Newtown's last and first frost, putting it 24,576 of 40,283 ZIP codes nationally. Within CT, it ranks 251 of 391.
Learn more
Two guides worth reading on 06488: local microclimates, on what one yard in Newtown can differ from the 06488 normal, and zone vs. frost date, on why Zone 6b and Newtown's frost date answer different questions.