SmogRank / Countries / United States / Connecticut
Most polluted cities in Connecticut, United States
6 measured cities ranked by PM2.5, last 30 days. Worst: New Haven at 4.4 µg/m³, #2013 in the world.
| # | City | µg/m³ | |
|---|---|---|---|
| 1 | New Haven Connecticut | 4.4 | |
| 2 | Waterbury Connecticut | 4.4 | |
| 3 | Hartford Connecticut | 4.3 | |
| 4 | Bridgeport Connecticut | 4.2 | |
| 5 | Danbury Connecticut | 4.1 | |
| 6 | New London Connecticut | 3.5 |
Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data
Estimated: cities without a monitor
Connecticut cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Stamford estimated | ≈ 2 µg/m³ |
| North Stamford estimated | ≈ 2 µg/m³ |
| Norwalk estimated | ≈ 2 µg/m³ |
| East Norwalk estimated | ≈ 2 µg/m³ |
| New Britain estimated | ≈ 3 µg/m³ |
| West Hartford estimated | ≈ 3 µg/m³ |
| Bristol estimated | ≈ 3 µg/m³ |
| Meriden estimated | ≈ 3 µg/m³ |
| Hamden estimated | ≈ 3 µg/m³ |
| Fairfield estimated | ≈ 2 µg/m³ |
| West Haven estimated | ≈ 2 µg/m³ |
| Milford estimated | ≈ 2 µg/m³ |
| Stratford estimated | ≈ 2 µg/m³ |
| City of Milford (balance) estimated | ≈ 2 µg/m³ |
| East Hartford estimated | ≈ 3 µg/m³ |
| Middletown estimated | ≈ 3 µg/m³ |
| Enfield estimated | ≈ 3 µg/m³ |
| Southington estimated | ≈ 3 µg/m³ |
| Shelton estimated | ≈ 2 µg/m³ |
| Norwich estimated | ≈ 2 µg/m³ |
| Trumbull estimated | ≈ 2 µg/m³ |
| West Torrington estimated | ≈ 2 µg/m³ |
| Torrington estimated | ≈ 2 µg/m³ |
| Glastonbury estimated | ≈ 3 µg/m³ |
| Naugatuck estimated | ≈ 2 µg/m³ |
| Manchester estimated | ≈ 2 µg/m³ |
| Newington estimated | ≈ 3 µg/m³ |
| Cheshire estimated | ≈ 3 µg/m³ |
| Branford estimated | ≈ 2 µg/m³ |
| East Haven estimated | ≈ 2 µg/m³ |
| Windsor estimated | ≈ 2 µg/m³ |
| Wethersfield estimated | ≈ 3 µg/m³ |
| Mansfield City estimated | ≈ 3 µg/m³ |
| Westport estimated | ≈ 2 µg/m³ |
| Farmington estimated | ≈ 3 µg/m³ |
| South Windsor estimated | ≈ 2 µg/m³ |
| North Haven estimated | ≈ 3 µg/m³ |
| Windham estimated | ≈ 2 µg/m³ |
| Guilford estimated | ≈ 2 µg/m³ |
| Bloomfield estimated | ≈ 2 µg/m³ |
Updated 2026-10-01 10:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.