Connecticut(CT)
Air quality overview and monitoring data — 2025
236
Monitoring Sites
5,516
Active Monitors
8
Counties with Data
58
Cities Monitored
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County Air Quality
| County | Median AQI ▲ | 90th %ile | Max AQI | Good | Moderate | USG | Unhealthy |
|---|---|---|---|---|---|---|---|
| Windham | 37 | 50 | 108 | 219 | 21 | 1 | 0 |
| New London | 40 | 59 | 136 | 143 | 34 | 4 | 0 |
| Litchfield | 41 | 64 | 161 | 148 | 29 | 3 | 1 |
| Middlesex | 42 | 77 | 151 | 95 | 25 | 1 | 1 |
| Tolland | 42 | 64 | 136 | 95 | 21 | 3 | 0 |
| Fairfield | 44 | 69 | 166 | 121 | 51 | 8 | 1 |
| Hartford | 44 | 68 | 164 | 121 | 56 | 3 | 1 |
| New Haven | 44 | 67 | 151 | 124 | 52 | 4 | 1 |
Pollutant Trends
Ozone
No data available
PM2.5
No data available
PM10
No data available
CO
No data available
NO2
No data available
SO2
No data available