Processed on 2024-03-04 13:21:07 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 January.

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.

January in Massachusetts

January 2014 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 179 72 0 0 0 0 28
New 115 136 0 0 0 0 28

January 2015 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 227 45 0 0 0 0 7
New 172 100 0 0 0 0 7

January 2016 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 228 25 0 0 0 0 26
New 189 64 0 0 0 0 26

January 2017 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 252 17 0 0 0 0 10
New 228 41 0 0 0 0 10

January 2018 – 24 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 238 69 0 0 0 0 3
New 180 127 0 0 0 0 3

January 2019 – 14 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 345 49 0 0 0 0 40
New 252 142 0 0 0 0 40

January 2020 – 28 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 366 55 0 0 0 0 13
New 289 131 1 0 0 0 13

January 2021 – 17 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 386 63 0 0 0 0 16
New 330 119 0 0 0 0 16

January 2022 – 17 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 385 124 0 0 0 0 18
New 288 221 0 0 0 0 18

January 2023 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 497 30 0 0 0 0 0
New 414 113 0 0 0 0 0