Processed on 2024-03-04 13:20:06 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 July.

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.

July in Maryland

July 2014 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 189 78 0 0 0 0 21
New 90 177 0 0 0 0 21

July 2015 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 163 94 0 0 0 0 31
New 99 158 0 0 0 0 31

July 2016 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 260 41 0 0 0 0 19
New 191 110 0 0 0 0 19

July 2017 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 243 32 0 0 0 0 13
New 181 94 0 0 0 0 13

July 2018 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 274 34 0 0 0 0 12
New 216 92 0 0 0 0 12

July 2019 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 279 31 0 0 0 0 10
New 177 133 0 0 0 0 10

July 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 341 30 0 0 0 0 13
New 266 105 0 0 0 0 13

July 2021 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 236 128 3 0 0 0 17
New 156 208 3 0 0 0 17

July 2022 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 376 22 0 0 0 0 18
New 299 99 0 0 0 0 18

July 2023 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 322 79 1 0 0 0 14
New 256 145 1 0 0 0 14