Processed on 2024-03-04 13:23:29 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 Michigan 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 Michigan

March 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 42 20 0 0 0 0 0
New 15 47 0 0 0 0 0

March 2015 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 47 15 0 0 0 0 0
New 33 29 0 0 0 0 0

March 2016 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 23 8 0 0 0 0 0
New 13 18 0 0 0 0 0

March 2017 – 1 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 27 4 0 0 0 0 0
New 18 13 0 0 0 0 0

March 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 31 0 0 0 0 0 0
New 25 6 0 0 0 0 0

March 2019 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 23 8 0 0 0 0 0
New 12 19 0 0 0 0 0

March 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 45 16 0 0 0 0 1
New 27 34 0 0 0 0 1

March 2021 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 133 32 0 0 0 0 424
New 110 55 0 0 0 0 424

March 2022 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 439 141 4 0 0 0 36
New 350 230 4 0 0 0 36

March 2023 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 477 171 2 0 0 0 1
New 348 300 2 0 0 0 1