Processed on 2024-03-04 13:49:52 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 Ohio 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 Ohio

May 2014 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 311 152 0 0 0 0 49
New 211 252 0 0 0 0 49

May 2015 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 285 204 0 0 0 0 23
New 170 319 0 0 0 0 23

May 2016 – 32 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 392 96 0 0 0 0 24
New 274 214 0 0 0 0 24

May 2017 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 482 56 0 0 0 0 38
New 384 154 0 0 0 0 38

May 2018 – 39 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 371 144 1 0 0 0 60
New 253 262 1 0 0 0 60

May 2019 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 474 90 0 0 0 0 44
New 341 223 0 0 0 0 44

May 2020 – 40 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 586 14 0 0 0 0 40
New 528 72 0 0 0 0 40

May 2021 – 24 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 483 142 0 0 0 0 47
New 392 233 0 0 0 0 47

May 2022 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 698 61 0 0 0 0 73
New 550 209 0 0 0 0 73

May 2023 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 774 186 0 0 0 0 64
New 558 402 0 0 0 0 64