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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 Thursday, 12/04/25

Good
AQI Scale

For current conditions, see map below.

Cautionary Statements

AQI Forecast

Forecast for Thursday, 12/04/25

Good

Forecast for Friday, 12/05/25

Good

For local forecasts, see table below.

Restrictions For Regulated Community

Ozone forecasting has come to a close. Ozone concentrations from October through April are expected to remain in the GOOD, to occasionally MODERATE range.

For details, see operating restrictions page.

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

AIRNOW Interactive Map of Air Quality

Local AQI Forecast

Town Thursday, 12/04/25
FineParticles (PM2.5)		 Thursday, 12/04/25
Ozone (O3)		 Friday, 12/05/25
FineParticles (PM2.5)		 Friday, 12/05/25
Ozone (O3)
Bridgeport 50 28
Danbury 44 17
Greenwich 50 28
Hartford 50 22
Madison 39 12
Middletown 50 22
New Haven 50 17
New London-Groton 39 17
Stafford 33 17
Stratford 50 28
Torrington 33 17
Waterbury 44 22
Westport 50 28
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.