Processed on 2024-03-04 13:29:32 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 April.

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.

April in Missouri

April 2014 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 273 82 0 0 0 0 17
New 202 153 0 0 0 0 17

April 2015 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 317 51 0 0 0 0 35
New 254 114 0 0 0 0 35

April 2016 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 359 13 0 0 0 0 31
New 287 85 0 0 0 0 31

April 2017 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 314 12 0 0 0 0 15
New 261 65 0 0 0 0 15

April 2018 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 333 27 0 0 0 0 12
New 267 93 0 0 0 0 12

April 2019 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 315 38 0 0 0 0 19
New 263 90 0 0 0 0 19

April 2020 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 362 22 0 0 0 0 19
New 329 55 0 0 0 0 19

April 2021 – 14 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 342 36 0 0 0 0 25
New 291 87 0 0 0 0 25

April 2022 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 340 15 0 0 0 0 17
New 313 42 0 0 0 0 17

April 2023 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 325 29 0 0 0 0 18
New 277 77 0 0 0 0 18