New Haven, CT 06521 Frost Dates
When can you plant in New Haven, CT?
Typically, the last spring freeze lands around 04/17, roughly 232 days out. The first fall frost typically arrives around 10/27, about 193 frost-free days later.
New Haven 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.
What to do before the first frost
About 9 weeks of growing season left in New Haven before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around New Haven's last frost
04/17 is the middle of 30 years of NOAA records, not a promise. Plant by 04/02 and you're betting against frost in roughly 9 years out of 10. 05/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How New Haven compares
New Haven's growing season runs about 193 days, ranking 19,702 of 40,283 US ZIP codes measured here, longest to shortest. Within CT, it ranks 78 of 391.
Learn more
local microclimates covers what one yard in New Haven can differ from the 06521 normal. zone vs. frost date covers why Zone 7a and New Haven's frost date answer different questions.