Processed on 2024-03-04 13:24:10 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 July.

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.

July in Michigan

July 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 34 25 3 0 0 0 2
New 23 36 3 0 0 0 2

July 2015 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 31 28 2 1 0 0 2
New 24 35 2 1 0 0 2

July 2016 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 19 8 0 0 0 0 5
New 9 18 0 0 0 0 5

July 2017 – 1 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 23 8 0 0 0 0 1
New 11 20 0 0 0 0 1

July 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 19 12 0 0 0 0 1
New 10 21 0 0 0 0 1

July 2019 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 15 16 0 0 0 0 1
New 11 20 0 0 0 0 1

July 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 38 19 3 1 0 0 3
New 26 31 3 1 0 0 3

July 2021 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 313 257 1 0 0 0 37
New 212 358 1 0 0 0 37

July 2022 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 567 72 0 0 0 0 33
New 395 244 0 0 0 0 33

July 2023 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 343 243 17 1 0 0 68
New 208 377 18 1 0 0 68