Processed on 2024-03-04 12:53:59 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 May.

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.

May in Connecticut

May 2014 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 215 20 0 0 0 0 21
New 186 49 0 0 0 0 21

May 2015 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 170 50 0 0 0 0 36
New 122 98 0 0 0 0 36

May 2016 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 178 31 0 0 0 0 15
New 160 49 0 0 0 0 15

May 2017 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 190 9 0 0 0 0 57
New 182 17 0 0 0 0 57

May 2018 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 208 36 0 0 0 0 12
New 179 65 0 0 0 0 12

May 2019 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 235 13 0 0 0 0 8
New 217 31 0 0 0 0 8

May 2020 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 243 5 0 0 0 0 8
New 236 12 0 0 0 0 8

May 2021 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 232 10 0 0 0 0 14
New 208 34 0 0 0 0 14

May 2022 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 232 12 0 0 0 0 12
New 207 37 0 0 0 0 12

May 2023 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 229 19 0 0 0 0 8
New 195 53 0 0 0 0 8