Processed on 2024-03-04 13:23:19 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 February.

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.

February in Michigan

February 2014 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 29 23 0 0 0 0 4
New 15 37 0 0 0 0 4

February 2015 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 26 30 0 0 0 0 0
New 11 45 0 0 0 0 0

February 2016 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 30 3 0 0 0 0 25
New 19 14 0 0 0 0 25

February 2017 – 1 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 19 9 0 0 0 0 0
New 11 17 0 0 0 0 0

February 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 23 5 0 0 0 0 0
New 5 23 0 0 0 0 0

February 2019 – 2 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 22 6 0 0 0 0 0
New 16 12 0 0 0 0 0

February 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 40 16 0 0 0 0 2
New 25 31 0 0 0 0 2

February 2021 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 28 27 0 0 0 0 1
New 17 38 0 0 0 0 1

February 2022 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 368 177 0 0 0 0 15
New 269 276 0 0 0 0 15

February 2023 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 439 136 0 0 0 0 13
New 273 302 0 0 0 0 13