Processed on 2024-03-04 12:45:40 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 Arizona 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 Arizona

May 2014 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 435 51 0 1 0 0 9
New 351 135 0 1 0 0 9

May 2015 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 456 1 0 0 0 0 8
New 448 9 0 0 0 0 8

May 2016 – 34 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 459 5 0 0 0 0 32
New 434 30 0 0 0 0 32

May 2017 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 493 25 1 1 0 0 7
New 456 62 1 1 0 0 7

May 2018 – 36 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 509 11 0 0 0 0 7
New 470 50 0 0 0 0 7

May 2019 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 474 13 0 0 0 0 9
New 464 23 0 0 0 0 9

May 2020 – 39 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 529 20 1 0 0 0 8
New 487 62 1 0 0 0 8

May 2021 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 602 36 1 0 0 0 12
New 539 99 1 0 0 0 12

May 2022 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 576 56 0 0 0 0 19
New 474 158 0 0 0 0 19

May 2023 – 33 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 604 18 0 0 0 0 29
New 542 80 0 0 0 0 29