Processed on 2024-03-04 13:20:17 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 Maryland spent in each AQI category during the the month of August.

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.

August in Maryland

August 2014 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 189 78 0 0 0 0 21
New 123 144 0 0 0 0 21

August 2015 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 218 50 0 0 0 0 20
New 150 118 0 0 0 0 20

August 2016 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 280 18 0 0 0 0 22
New 234 64 0 0 0 0 22

August 2017 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 238 29 0 0 0 0 21
New 136 131 0 0 0 0 21

August 2018 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 248 48 0 0 0 0 24
New 188 108 0 0 0 0 24

August 2019 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 299 10 0 0 0 0 11
New 252 57 0 0 0 0 11

August 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 361 9 0 0 0 0 14
New 310 60 0 0 0 0 14

August 2021 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 332 28 0 0 0 0 24
New 248 112 0 0 0 0 24

August 2022 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 386 11 0 0 0 0 19
New 338 59 0 0 0 0 19

August 2023 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 364 33 0 0 0 0 19
New 294 103 0 0 0 0 19