Connecticut Planting Zones
Connecticut runs from zone 6a to zone 7b on the 2023 USDA map. Zone 6b is the most common, covering 60% of the state's ZIP codes. Bridgeport is 7a, New Haven is 7a and Hartford is 6b.
Zones across Connecticut
| Zone | Average coldest night | Share of Connecticut ZIP codes |
|---|---|---|
| 6a | −10 to −5°F | 12% |
| 6b | −5 to 0°F | 60% |
| 7a | 0 to 5°F | 27% |
| 7b | 5 to 10°F | under 1% |
Planting zone for every city and town in Connecticut
Each Connecticut town uses the ZIP code at its center. Big towns can cross into the next half-zone, so look up your own ZIP if you're near a line.
| City | Zone | Average coldest night |
|---|---|---|
| Ansonia | 6b | −5 to 0°F |
| Bantam | 6a | −10 to −5°F |
| Bridgeport | 7a | 0 to 5°F |
| Bristol | 6b | −5 to 0°F |
| Danbury | 6b | −5 to 0°F |
| Danielson | 6b | −5 to 0°F |
| Derby | 6b | −5 to 0°F |
| Fenwick | 7a | 0 to 5°F |
| Groton | 7a | 0 to 5°F |
| Groton Long Point | 7a | 0 to 5°F |
| Hartford | 6b | −5 to 0°F |
| Jewett City | 6b | −5 to 0°F |
| Litchfield | 6a | −10 to −5°F |
| Meriden | 6b | −5 to 0°F |
| Middletown | 6b | −5 to 0°F |
| Milford | 7a | 0 to 5°F |
| Naugatuck | 6b | −5 to 0°F |
| New Britain | 6b | −5 to 0°F |
| New Haven | 7a | 0 to 5°F |
| New London | 7a | 0 to 5°F |
| Newtown | 6b | −5 to 0°F |
| Norwalk | 7a | 0 to 5°F |
| Norwich | 6b | −5 to 0°F |
| Shelton | 6b | −5 to 0°F |
| Stamford | 7a | 0 to 5°F |
| Stonington | 7a | 0 to 5°F |
| Torrington | 6a | −10 to −5°F |
| Waterbury | 6b | −5 to 0°F |
| West Haven | 7a | 0 to 5°F |
| Woodmont | 7a | 0 to 5°F |
Source: USDA Plant Hardiness Zone Map, 2023, Agricultural Research Service, U.S. Department of Agriculture; ZIP code table from the PRISM Group, Oregon State University (accessed Oct 2026). This list is our own summary, not the official USDA map. See how we calculate.
Frequently asked questions
What planting zone is Connecticut?
Connecticut spans zones 6a to 7b on the 2023 USDA map, and zone 6b is the most common. Look up your ZIP code for your exact zone.
What zone is Bridgeport, CT?
Bridgeport is zone 7a, where the coldest night of an average winter falls from 0 to 5°F. Plants rated hardy to zone 7 or colder should survive a typical winter there.
More for Connecticut: Connecticut climate zones (insulation) · Last frost dates in Connecticut · Frost line depth by state