Processed on 2024-03-04 13:29:42 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 Missouri spent in each AQI category during the the month of May.

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.

May in Missouri

May 2014 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 276 79 1 0 0 0 28
New 169 186 1 0 0 0 28

May 2015 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 364 38 0 0 0 0 14
New 299 103 0 0 0 0 14

May 2016 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 371 23 1 0 0 0 21
New 329 65 1 0 0 0 21

May 2017 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 316 24 0 0 0 0 12
New 235 105 0 0 0 0 12

May 2018 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 323 42 0 0 0 0 19
New 204 161 0 0 0 0 19

May 2019 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 333 13 0 0 0 0 38
New 285 61 0 0 0 0 38

May 2020 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 399 0 0 0 0 0 17
New 372 27 0 0 0 0 17

May 2021 – 14 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 388 10 0 0 0 0 18
New 352 46 0 0 0 0 18

May 2022 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 307 46 0 0 0 0 31
New 274 79 0 0 0 0 31

May 2023 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 282 77 0 0 0 0 25
New 193 166 0 0 0 0 25