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 Monday, 05/18/26

Good to Moderate

For current conditions, see map below.

Cautionary Statements

AQI Forecast

Forecast for Monday, 05/18/26

Good to Moderate

For local forecasts, see table below.

Restrictions For Regulated Community

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

For more information, visit the AIRNow Interactive Map of Air Quality website.

Local AQI Forecast

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

Receive AQI Notices

DEEP Air Quality Information
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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.