Processed on 2024-03-04 13:50:31 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 September.

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.

September in Ohio

September 2014 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 345 123 0 0 0 0 28
New 224 244 0 0 0 0 28

September 2015 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 331 140 0 0 0 0 25
New 229 242 0 0 0 0 25

September 2016 – 32 permanent monitors

September 2017 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 377 136 0 0 0 0 45
New 288 225 0 0 0 0 45

September 2018 – 39 permanent monitors

Processing error: Unable to calculate tables.

September 2019 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 436 98 0 0 0 0 24
New 312 222 0 0 0 0 24

September 2020 – 40 permanent monitors

Processing error: Unable to calculate tables.

September 2021 – 24 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 547 70 0 0 0 0 34
New 423 194 0 0 0 0 34

September 2022 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 683 93 0 0 0 0 30
New 565 211 0 0 0 0 30

September 2023 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1008 54 0 0 0 0 85
New 814 248 0 0 0 0 85