Processed on 2024-03-04 13:24:21 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 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 Michigan

August 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 24 34 0 0 0 0 6
New 11 47 0 0 0 0 6

August 2015 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 45 17 0 0 0 0 2
New 32 30 0 0 0 0 2

August 2016 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 13 11 0 0 0 0 8
New 7 17 0 0 0 0 8

August 2017 – 1 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 18 13 0 0 0 0 1
New 8 23 0 0 0 0 1

August 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 10 21 0 0 0 0 1
New 2 29 0 0 0 0 1

August 2019 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 27 4 0 0 0 0 1
New 16 15 0 0 0 0 1

August 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 42 17 0 0 0 0 5
New 28 31 0 0 0 0 5

August 2021 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 333 245 1 0 0 0 29
New 161 417 1 0 0 0 29

August 2022 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 547 39 0 0 0 0 86
New 425 161 0 0 0 0 86

August 2023 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 366 277 0 0 0 0 29
New 264 379 0 0 0 0 29