Danbury, CT 06810 Frost Dates
06810, near Danbury, CT: the frost window
Typically, the last spring freeze lands around 04/20, roughly 235 days out. Fall's first freeze usually shows up around 10/20, roughly 181 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 Danbury, not a forecast for this year.
Stretching the season past the first frost
Danbury'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.
Danbury against the rest of the dataset
About 181 days separate Danbury's last and first frost, putting it 24,431 of 40,283 ZIP codes nationally. Within CT, it ranks 242 of 391.
Learn more
Two guides worth reading on 06810: the frost range, on how to read the range around Danbury's dates instead of trusting one, and local microclimates, on what one yard in Danbury can differ from the 06810 normal.