Processed on 2024-03-04 13:17:43 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 Maine 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 Maine

May 2014 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 64 0 0 0 0 0 32
New 64 0 0 0 0 0 32

May 2015 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 172 8 0 0 0 0 12
New 153 27 0 0 0 0 12

May 2016 – 15 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 171 6 0 0 0 0 15
New 166 11 0 0 0 0 15

May 2017 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 167 2 0 0 0 0 23
New 163 6 0 0 0 0 23

May 2018 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 206 3 0 1 0 0 14
New 189 20 0 1 0 0 14

May 2019 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 238 2 0 0 0 0 16
New 235 5 0 0 0 0 16

May 2020 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 227 2 0 0 0 0 27
New 224 5 0 0 0 0 27

May 2021 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 238 4 0 0 0 0 14
New 231 11 0 0 0 0 14

May 2022 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 196 1 0 0 0 0 27
New 196 1 0 0 0 0 27

May 2023 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 243 4 0 0 0 0 41
New 230 17 0 0 0 0 41