Processed on 2024-03-04 12:52:13 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 Colorado spent in each AQI category during the the month of June.

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.

June in Colorado

June 2014 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 287 4 0 0 0 0 50
New 266 25 0 0 0 0 50

June 2015 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 242 23 0 0 0 0 45
New 184 81 0 0 0 0 45

June 2016 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 274 40 0 0 0 0 27
New 207 107 0 0 0 0 27

June 2017 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 333 11 0 0 0 0 59
New 277 67 0 0 0 0 59

June 2018 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 372 19 0 0 0 0 43
New 307 84 0 0 0 0 43

June 2019 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 368 1 0 0 0 0 65
New 358 11 0 0 0 0 65

June 2020 – 39 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 409 20 0 0 0 0 36
New 378 51 0 0 0 0 36

June 2021 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 377 63 1 0 0 0 86
New 276 164 1 0 0 0 86

June 2022 – 34 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 463 22 0 0 0 0 42
New 418 67 0 0 0 0 42

June 2023 – 147 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 465 7 0 0 0 0 24
New 434 38 0 0 0 0 24