New Haven, CT 06509 Frost Dates
Frost dates for New Haven, CT, ZIP 06509
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
Zone 7a around New Haven has about 9 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/17 isn't a guarantee
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 19,692 of 40,283 US ZIP codes measured here, longest to shortest. Within CT, it ranks 68 of 391.
Learn more
local microclimates explains what one yard in New Haven can differ from the 06509 normal, and zone vs. frost date explains why Zone 7a and New Haven's frost date answer different questions.