Processed on 2024-03-04 12:45:30 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 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 Arizona

April 2014 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 353 16 0 0 0 0 111
New 311 58 0 0 0 0 111

April 2015 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 416 5 0 0 0 0 29
New 383 38 0 0 0 0 29

April 2016 – 34 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 402 10 0 0 0 0 38
New 370 42 0 0 0 0 38

April 2017 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 464 35 0 0 0 0 11
New 388 111 0 0 0 0 11

April 2018 – 36 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 472 33 0 0 0 0 5
New 392 113 0 0 0 0 5

April 2019 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 455 14 0 0 0 0 11
New 435 34 0 0 0 0 11

April 2020 – 39 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 513 8 0 0 0 0 19
New 490 31 0 0 0 0 19

April 2021 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 572 41 0 0 0 0 17
New 489 124 0 0 0 0 17

April 2022 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 527 85 1 0 0 0 17
New 397 215 1 0 0 0 17

April 2023 – 33 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 552 51 0 0 0 0 27
New 455 147 1 0 0 0 27