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Air Quality Index

The U. S. Environmental Protection Agency (EPA) has provided a scale called the Air Quality Index (AQI) for rating air quality. This scale is based on the National Ambient Air Quality Standards (NAAQS). The AQI forecast is updated once daily, excluding weekends and holidays. Alternatively, you may call the Air Quality Index Hotline at (800) 249-1234 or (860) 424-4167 for the forecast or link to Airnow.gov for the most current air quality information.

Current air quality is provided below the AQI forecast section.

Current Air Quality

Air Quality for Sunday, 05/17/26

Moderate to Unhealthy For Sensitive Groups
AQI Scale

For current conditions, see map below.

Cautionary Statements

AQI Forecast

Forecast for Sunday, 05/17/26

Good to Moderate

Forecast for Monday, 05/18/26

Good to Moderate

For local forecasts, see table below.

Restrictions For Regulated Community

Sunday, 05/17/26

Restrictions Do Not Apply

Monday, 05/18/26

Restrictions Do Not Apply

For details, see operating restrictions page.

Historical Ozone Data
Forecasted Ozone Exceedance Days
Tips for Ozone Action Days
Air Monitoring in Connecticut

Local AQI Forecast

Town Sunday, 05/17/26
FineParticles (PM2.5)		 Sunday, 05/17/26
Ozone (O3)		 Monday, 05/18/26
FineParticles (PM2.5)		 Monday, 05/18/26
Ozone (O3)
Bridgeport 58 54 56 54
Danbury 56 50 56 58
Greenwich 58 54 56 61
Hartford 58 49 56 50
Madison 50 54 50 48
Middletown 58 50 56 48
New Haven 54 51 52 49
New London-Groton 50 51 50 48
Stafford 50 45 54 47
Stratford 58 54 56 54
Torrington 50 44 54 49
Waterbury 56 50 56 48
Westport 58 51 56 58

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If you have any questions regarding the Air Quality Forecast, please contact the Bureau of Air Management by phone at (860) 424-4152 or by email.