Processed on 2024-03-04 13:19:05 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 January.

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.

January in Maryland

January 2014 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 191 51 0 0 0 0 6
New 151 91 0 0 0 0 6

January 2015 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 178 85 0 0 0 0 16
New 111 152 0 0 0 0 16

January 2016 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 216 62 1 0 0 0 31
New 154 123 2 0 0 0 31

January 2017 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 265 37 0 0 0 0 8
New 226 76 0 0 0 0 8

January 2018 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 234 67 0 0 0 0 9
New 176 125 0 0 0 0 9

January 2019 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 277 33 0 0 0 0 0
New 246 64 0 0 0 0 0

January 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 294 12 0 0 0 0 4
New 276 30 0 0 0 0 4

January 2021 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 313 48 0 0 0 0 11
New 274 87 0 0 0 0 11

January 2022 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 301 63 0 0 0 0 39
New 236 128 0 0 0 0 39

January 2023 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 358 21 0 0 0 0 24
New 312 67 0 0 0 0 24