What does USDA hardiness zone 7b mean in Connecticut?

Zone 7b means an average annual extreme minimum winter temperature of 5 to 10 °F — the standard USDA measure of which perennials survive winter. 1 location in Connecticut fall in this zone. It does not set planting dates; see the frost calendar below for that.

When should I plant tomatoes in Connecticut's zone 7b?

Using Norwalk's frost dates (this page's median-season location): start seeds indoors about Feb 20 – Mar 6, then transplant outside about Apr 24 – May 1. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.

Does every location in Connecticut's zone 7b have the same frost dates?

No — they do not all share a weather station, so frost dates vary by a week or more across the 1 locations listed (see the table above for each location's own dates).

USDA zone 7b in Connecticut

5 to 10 °F avg. annual extreme minimum · 1 location in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 7b covers 1 location across Connecticut (average annual extreme minimum 5 to 10 °F): Norwalk, CT. Average last spring frost across this group ranges April 17 and growing seasons run 188 days — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Connecticut location's own frost dates; the printable planting calendar uses Norwalk, this group's median-season location.

USDA zone: 7b5 to 10 °F
Last frost range: Apr 17avg, 32°F
First frost range: Oct 23avg, 32°F
Growing season range: 188days

Locations in this group

Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.

Own frost dates per location.
Location	Also covers	Nearest station	Last frost	First frost	Season (days)
Norwalk *	—	Stamford 5 N	Apr 17	Oct 23	188

* Norwalk is this group's median-season location — the calendar below is computed from its data.

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.

Planting calendar (Norwalk, representative)

Computed from Norwalk's average frost dates — the median-season location in this Connecticutzone 7b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).

Crop

JanFebMarAprMayJunJulAugSepOctNovDec

Tomato

Pepper

Cucumber

Summer squash / zucchini

Start indoors
Plant out
Fall sowing
First harvest

Planting windows for Norwalk (Connecticut, zone 7b), this group's representative location.
Crop	Frost tolerance	Start indoors	Plant out	First harvest	Fall planting	Season fit
Tomato	Tender	Feb 20 – Mar 6	Apr 24 – May 1	Jun 23 – Jul 13	—	matures comfortably
Pepper	Very tender	Feb 6 – Feb 20	May 1 – May 8	Jun 30 – Jul 30	—	matures comfortably
Cucumber	Tender	Mar 20 – Mar 27	Apr 24 – May 1	Jun 13 – Jul 3	—	matures comfortably
Summer squash / zucchini	Tender	—	Apr 24 – May 1	Jun 8 – Jun 23	—	matures comfortably
Bush bean	Tender	—	Apr 24 – May 1	Jun 13 – Jun 23	Aug 24 – Sep 3	matures comfortably
Sweet corn	Tender	—	Apr 17 – May 1	Jun 16 – Jul 16	—	matures comfortably
Basil	Very tender	Mar 6 – Mar 20	Apr 24 – May 1	May 24 – Jun 8	—	matures comfortably
Lettuce	Half-hardy	Mar 6 – Mar 20	Mar 20 – Apr 3	May 4 – May 19	Aug 10 – Aug 25	matures comfortably
Pea	Hardy	—	Mar 6 – Mar 20	Apr 30 – May 15	Jul 31 – Aug 15	matures comfortably
Spinach	Hardy	—	Mar 6 – Mar 20	Apr 15 – Apr 25	Aug 20 – Aug 30	matures comfortably
Carrot	Half-hardy	—	Mar 27 – Apr 3	May 26 – Jun 15	Jul 21 – Aug 10	matures comfortably
Broccoli	Half-hardy	Feb 20 – Mar 6	Mar 20 – Apr 3	May 14 – Jun 3	Jul 26 – Aug 15	matures comfortably

Which crops fit this growing season

Using Norwalk's own 188-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.

Frost & freeze dates (Norwalk)

From NOAA's 1991–2020 Climate Normals at station USC00067970. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Norwalk.
Threshold	Last spring — avg	Last spring — 90%-safe	First fall — avg	First fall — 90%-safe	Season (days)
36°F	Apr 30	May 16	Oct 12	Oct 25	163
32°F (freeze)	Apr 17	May 2	Oct 23	Nov 6	188
28°F	Apr 3	Apr 19	Nov 2	Nov 19	212
24°F	Mar 24	Apr 5	Nov 17	Dec 4	237

Growing degree days

Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 1 locations is 3,227; Norwalk's own reading is shown below.

Annual growing degree days for Norwalk (°F·days, NOAA 1991–2020).
Model	°F·days	Used for
Base 50°F (warm-season)	3,227	standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)	5,552	cool-season crops (brassicas, greens)

Hardiness zone 7b in Connecticut

Zone 7b means an average annual extreme minimum winter temperature of about 5 to 10 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Connecticut spans 5 hardiness zones in this dataset — see all Connecticut locations for the full range, including zones5b, 6a, 6b, 7a.

Explore zone 7b in other states at zone 7b, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 7b mean in Connecticut?: Zone 7b means an average annual extreme minimum winter temperature of 5 to 10 °F — the standard USDA measure of which perennials survive winter. 1 location in Connecticut fall in this zone. It does not set planting dates; see the frost calendar below for that.
When should I plant tomatoes in Connecticut's zone 7b?: Using Norwalk's frost dates (this page's median-season location): start seeds indoors about Feb 20 – Mar 6, then transplant outside about Apr 24 – May 1. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
Does every location in Connecticut's zone 7b have the same frost dates?: No — they do not all share a weather station, so frost dates vary by a week or more across the 1 locations listed (see the table above for each location's own dates).

Sources & method

Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.