Processed on 2024-03-04 13:24:41 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 October.

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.

October in Michigan

October 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 51 9 0 0 0 0 4
New 39 21 0 0 0 0 4

October 2015 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 48 13 0 0 0 0 3
New 35 26 0 0 0 0 3

October 2016 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 23 6 0 0 0 0 3
New 16 13 0 0 0 0 3

October 2017 – 1 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 24 5 0 0 0 0 3
New 10 19 0 0 0 0 3

October 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 53 7 0 0 0 0 4
New 40 20 0 0 0 0 4

October 2019 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 26 4 0 0 0 0 2
New 23 7 0 0 0 0 2

October 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 56 4 0 0 0 0 4
New 47 13 0 0 0 0 4

October 2021 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 495 81 0 0 0 0 64
New 374 202 0 0 0 0 64

October 2022 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 445 190 1 0 0 0 36
New 328 307 1 0 0 0 36

October 2023 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 555 72 0 0 0 0 45
New 437 190 0 0 0 0 45