Processed on 2024-03-04 13:17:32 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 April.

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.

April in Maine

April 2014 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 49 0 0 0 0 0 44
New 48 1 0 0 0 0 44

April 2015 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 174 6 0 0 0 0 6
New 160 20 0 0 0 0 6

April 2016 – 15 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 155 7 0 0 0 0 24
New 132 30 0 0 0 0 24

April 2017 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 166 4 0 0 0 0 16
New 154 16 0 0 0 0 16

April 2018 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 196 6 0 0 0 0 15
New 186 16 0 0 0 0 15

April 2019 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 231 1 0 0 0 0 16
New 227 5 0 0 0 0 16

April 2020 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 225 1 0 0 0 0 22
New 216 10 0 0 0 0 22

April 2021 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 239 1 0 0 0 0 8
New 238 2 0 0 0 0 8

April 2022 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 179 0 0 0 0 0 38
New 179 0 0 0 0 0 38

April 2023 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 234 1 0 0 0 0 13
New 226 9 0 0 0 0 13