Processed on 2024-03-04 13:22:19 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 Massachusetts spent in each AQI category during the the month of August.

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.

August in Massachusetts

August 2014 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 221 43 0 0 0 0 24
New 139 125 0 0 0 0 24

August 2015 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 230 23 0 0 0 0 35
New 203 50 0 0 0 0 35

August 2016 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 262 1 0 0 0 0 25
New 242 21 0 0 0 0 25

August 2017 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 228 39 0 0 0 0 21
New 174 93 0 0 0 0 21

August 2018 – 24 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 302 82 0 0 0 0 32
New 250 134 0 0 0 0 32

August 2019 – 14 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 426 7 0 0 0 0 15
New 370 63 0 0 0 0 15

August 2020 – 28 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 411 13 0 0 0 0 24
New 306 118 0 0 0 0 24

August 2021 – 17 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 425 78 0 0 0 0 41
New 344 159 0 0 0 0 41

August 2022 – 17 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 464 8 0 0 0 0 72
New 408 64 0 0 0 0 72

August 2023 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 480 73 0 0 0 0 23
New 441 112 0 0 0 0 23