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When to plant in Willimantic, CT

USDA Zone 6b

Willimantic, 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 Willimantic sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.

Station · WILLIMANTIC WINDHAM AP · 3.7 km
Last spring frost
April 28
50% chance · 32°F
First fall frost
October 13
50% chance · 32°F
Growing season
168 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for WillimanticA year-band showing 32°F frost risk from January to December for Willimantic: last spring frost around April 28, first fall frost around October 13, about 168 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

WILLIMANTIC WINDHAM AP · 1991–2020

The 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 Willimantic’s own odds, recorded at WILLIMANTIC WINDHAM AP.

Frost-probability curves for WillimanticProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 28 and the first fall frost around October 13, giving about 168 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 22May 9Apr 27Sep 23Oct 3Oct 16
32°FMay 11Apr 28Apr 17Oct 2Oct 13Oct 29
28°FApr 29Apr 14Apr 2Oct 10Oct 25Nov 7

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Rutabaga
July 7July 21
Fall sowin 2 days
Broccoli
July 21August 4
Fall sowin 2 days
Cabbage
July 21August 4
Fall sowin 2 days
Carrot
July 21August 4
Fall sowin 2 days
Cauliflower
July 21August 4
Fall sowin 2 days
Napa Cabbage
July 21August 18
Fall sowin 16 days
Beet
August 4August 18
Fall sowin 16 days
Collards
August 4September 1
Fall sowin 16 days
Endive
August 4August 18
Fall sowin 16 days
Escarole
August 4August 18
Fall sowin 16 days
Fennel (Bulb)
August 4August 18
Fall sowin 16 days
Kale
August 4September 1
Fall sowin 16 days
Kohlrabi
August 4September 1
Fall sowin 16 days
Peas
August 4August 18
Fall sowin 16 days
Radicchio
August 4August 18
Fall sowin 16 days
Swiss Chard
August 4August 18
Fall sowin 16 days
Turnip
August 4September 1

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Willimantic, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 14 km · complete 32°F normals

When 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.

WILLIMANTIC WINDHAM AP
Primary
4 km · 75 m elevation
SPRING
Apr 28
FALL
Oct 13
STORRS
9 km · 203 m elevation
SPRING
Apr 19
FALL
Oct 22
HAMPTON
14 km · 149 m elevation
SPRING
Apr 30
FALL
Oct 15

Willimantic planting FAQ

When is the last spring frost in Willimantic, CT?

On average, the last spring frost in Willimantic is around April 28 (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 Willimantic, CT?

In Willimantic, the first 32°F freeze of fall lands around October 13 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Willimantic in?

Willimantic 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 Willimantic?

There are roughly 168 frost-free days in Willimantic (a moderate growing season), running from the average last frost around April 28 to the first fall frost near October 13.

When should I plant tomatoes in Willimantic?

In Willimantic, start tomato seeds indoors around March 3–March 17, then transplant seedlings outdoors around May 5 once the danger of frost has passed.

Planting reminders

Never miss a window in Willimantic

An email when it’s time to start seeds, transplant, and sow — timed to Willimantic’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at WILLIMANTIC WINDHAM AP, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Willimantic, CT — Frost Dates & Zone 6b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00054767. Retrieved from https://blissgarden.com/connecticut/willimantic.