Processed on 2024-03-04 12:51:34 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 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 Colorado

February 2014 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 210 72 8 1 0 0 17
New 176 106 8 1 0 0 17

February 2015 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 206 16 0 0 0 0 30
New 178 44 0 0 0 0 30

February 2016 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 250 29 0 0 0 0 40
New 223 56 0 0 0 0 40

February 2017 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 298 17 0 0 0 0 49
New 273 42 0 0 0 0 49

February 2018 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 282 73 3 0 0 0 6
New 228 127 3 0 0 0 6

February 2019 – 20 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 247 124 1 0 0 0 20
New 176 195 1 0 0 0 20

February 2020 – 39 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 339 40 0 0 0 0 27
New 295 84 0 0 0 0 27

February 2021 – 27 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 341 92 2 0 0 0 13
New 305 127 3 0 0 0 13

February 2022 – 34 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 397 45 0 0 0 0 6
New 360 82 0 0 0 0 6

February 2023 – 147 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 383 43 0 0 0 0 22
New 338 88 0 0 0 0 22