When to plant in North Haven, CT
USDA Zone 6bNorth Haven, Connecticut frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 6b means North Haven sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
The average first fall frost in North Haven is now 10 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
MT CARMEL · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are North Haven’s own odds, recorded at MT CARMEL.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 16 | May 1 | Apr 18 | Oct 2 | Oct 15 | Oct 30 |
| 32°F | May 3 | Apr 18 | Apr 5 | Oct 11 | Oct 26 | Nov 9 |
| 28°F | Apr 19 | Apr 5 | Mar 23 | Oct 22 | Nov 6 | Nov 22 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in North Haven, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
North Haven planting FAQ
When is the last spring frost in North Haven, CT?
On average, the last spring frost in North Haven is around April 18 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in North Haven, CT?
Expect North Haven's first fall frost near October 26 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is North Haven in?
North Haven is in USDA hardiness zone 6b. In zone 6b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in North Haven?
There are roughly 191 frost-free days in North Haven (a moderate growing season), running from the average last frost around April 18 to the first fall frost near October 26.
When should I plant tomatoes in North Haven?
In North Haven, start tomato seeds indoors around February 21–March 7, then transplant seedlings outdoors around April 25 once the danger of frost has passed.
Never miss a window in North Haven
An email when it’s time to start seeds, transplant, and sow — timed to North Haven’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Wallingford Center · 8 km
- New Haven · 10 km
- East Haven · 10 km
- West Haven · 15 km
- Orange · 18 km
- Meriden · 18 km
- Ansonia · 18 km
- Derby · 20 km
Frost dates recorded at MT CARMEL, 5 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in North Haven, CT — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00065077. Retrieved from https://blissgarden.com/connecticut/north-haven.