Processed on 2024-03-04 13:38:01 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 New Hampshire 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 New Hampshire

May 2014 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 143 1 0 0 0 0 16
New 129 15 0 0 0 0 16

May 2015 – 5 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 135 11 0 0 0 0 14
New 99 47 0 0 0 0 14

May 2016 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 130 11 0 0 0 0 19
New 122 19 0 0 0 0 19

May 2017 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 152 1 0 0 0 0 7
New 149 4 0 0 0 0 7

May 2018 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 148 2 0 0 0 0 10
New 133 17 0 0 0 0 10

May 2019 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 155 0 0 0 0 0 5
New 153 2 0 0 0 0 5

May 2020 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 150 1 0 0 0 0 9
New 145 6 0 0 0 0 9

May 2021 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 179 7 0 0 0 0 6
New 168 18 0 0 0 0 6

May 2022 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 183 1 0 0 0 0 8
New 176 8 0 0 0 0 8

May 2023 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 180 6 0 0 0 0 6
New 161 25 0 0 0 0 6