SmogRank / Countries / United States / Connecticut

Most polluted cities in Connecticut, United States

6 measured cities ranked by PM2.5, this year. Worst: Bridgeport at 7.5 µg/m³, #1616 in the world.

#City µg/m³× WHO
1Bridgeport Connecticut
7.51.5×
2Hartford Connecticut
7.41.5×
3Danbury Connecticut
7.31.5×
4Waterbury Connecticut
7.31.5×
5New Haven Connecticut
7.11.4×
6New London Connecticut
6.41.3×
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.

City7-day estimateBand
Stamford estimated≈ 2 µg/m³Good
North Stamford estimated≈ 2 µg/m³Good
Norwalk estimated≈ 2 µg/m³Good
East Norwalk estimated≈ 2 µg/m³Good
New Britain estimated≈ 3 µg/m³Good
West Hartford estimated≈ 3 µg/m³Good
Bristol estimated≈ 3 µg/m³Good
Meriden estimated≈ 3 µg/m³Good
Hamden estimated≈ 3 µg/m³Good
Fairfield estimated≈ 2 µg/m³Good
West Haven estimated≈ 2 µg/m³Good
Milford estimated≈ 2 µg/m³Good
Stratford estimated≈ 2 µg/m³Good
City of Milford (balance) estimated≈ 2 µg/m³Good
East Hartford estimated≈ 3 µg/m³Good
Middletown estimated≈ 3 µg/m³Good
Enfield estimated≈ 3 µg/m³Good
Southington estimated≈ 3 µg/m³Good
Shelton estimated≈ 2 µg/m³Good
Norwich estimated≈ 2 µg/m³Good
Trumbull estimated≈ 2 µg/m³Good
West Torrington estimated≈ 2 µg/m³Good
Torrington estimated≈ 2 µg/m³Good
Glastonbury estimated≈ 3 µg/m³Good
Naugatuck estimated≈ 2 µg/m³Good
Manchester estimated≈ 2 µg/m³Good
Newington estimated≈ 3 µg/m³Good
Cheshire estimated≈ 3 µg/m³Good
Branford estimated≈ 2 µg/m³Good
East Haven estimated≈ 2 µg/m³Good
Windsor estimated≈ 2 µg/m³Good
Wethersfield estimated≈ 3 µg/m³Good
Mansfield City estimated≈ 3 µg/m³Good
Westport estimated≈ 2 µg/m³Good
Farmington estimated≈ 3 µg/m³Good
South Windsor estimated≈ 2 µg/m³Good
North Haven estimated≈ 3 µg/m³Good
Windham estimated≈ 2 µg/m³Good
Guilford estimated≈ 2 µg/m³Good
Bloomfield estimated≈ 2 µg/m³Good

Updated 2026-10-01 09:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.