Processed on 2024-03-04 13:55:38 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 Pennsylvania spent in each AQI category during the the month of March.

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.

March in Pennsylvania

March 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 47 15 0 0 0 0 0
New 31 31 0 0 0 0 0

March 2015 – 3 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 46 16 0 0 0 0 0
New 34 28 0 0 0 0 0

March 2016 – 31 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 40 22 0 0 0 0 0
New 35 27 0 0 0 0 0

March 2017 – 3 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 72 21 0 0 0 0 0
New 61 32 0 0 0 0 0

March 2018 – 52 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 88 5 0 0 0 0 0
New 71 22 0 0 0 0 0

March 2019 – 28 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 359 187 4 0 0 0 39
New 244 302 4 0 0 0 39

March 2020 – 75 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 808 106 0 0 0 0 16
New 636 278 0 0 0 0 16

March 2021 – 42 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 587 145 1 0 0 0 538
New 473 259 1 0 0 0 538

March 2022 – 45 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 940 262 1 0 0 0 37
New 742 460 1 0 0 0 37

March 2023 – 46 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 977 142 2 0 0 0 26
New 764 355 2 0 0 0 26