Processed on 2024-03-04 14:12:34 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 Virginia 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 Virginia

September 2014 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 201 9 0 0 0 0 7
New 177 33 0 0 0 0 7

September 2015 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 183 26 0 0 0 0 8
New 170 39 0 0 0 0 8

September 2016 – 16 permanent monitors

Processing error: Unable to calculate tables.

September 2017 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 155 25 0 0 0 0 6
New 120 60 0 0 0 0 6

September 2018 – 12 permanent monitors

Processing error: Unable to calculate tables.

September 2019 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 189 11 0 0 0 0 17
New 148 52 0 0 0 0 17

September 2020 – 14 permanent monitors

Processing error: Unable to calculate tables.

September 2021 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 158 16 0 0 0 0 12
New 131 43 0 0 0 0 12

September 2022 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 250 16 0 0 0 0 13
New 213 53 0 0 0 0 13

September 2023 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 311 17 0 0 0 0 13
New 272 56 0 0 0 0 13