Processed on 2024-03-04 12:55:10 PST.


Disclaimer: Data presented here come from a variety of sources and do not represent official EPA measurements. Please visit AirNow for official measurements.


Cumulative exposure to smoke is an important public health metric. This report summarizes the cumulative number of days air quality monitors in Connecticut spent in each AQI category during the the month of December.

The tables below include only permanent monitors measuring PM2.5 and show cumulative exposure under existing NAAQS (National Ambient Air Quality Standards) and under the 2024 revised standards for PM2.5.

In the tables and plots below, ‘Old’ designates cumulative days calculated using the 2023 PM2.5 NAAQS while ‘New’ is calculated using the 2024 revised PM2.5 NAAQS. The impact of the NAAQS revision is quite clear.

December in Connecticut

December 2014 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 199 33 0 0 0 0 16
New 162 70 0 0 0 0 16

December 2015 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 181 45 0 0 0 0 22
New 159 67 0 0 0 0 22

December 2016 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 184 52 0 0 0 0 12
New 134 102 0 0 0 0 12

December 2017 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 198 34 0 0 0 0 16
New 162 70 0 0 0 0 16

December 2018 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 196 52 0 0 0 0 0
New 155 93 0 0 0 0 0

December 2019 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 201 43 0 0 0 0 4
New 162 82 0 0 0 0 4

December 2020 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 184 61 2 0 0 0 1
New 155 90 2 0 0 0 1

December 2021 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 181 67 0 0 0 0 0
New 133 115 0 0 0 0 0

December 2022 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 203 44 1 0 0 0 0
New 190 57 1 0 0 0 0

December 2023 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 171 43 0 0 0 0 26
New 142 72 0 0 0 0 26