Processed on 2024-03-04 14:09:10 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 Utah spent in each AQI category during the the month of December.

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.

December in Utah

December 2014 – 2 permanent monitors

December 2015 – 0 monitors in AirFire data archive

December 2016 – 15 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 156 25 1 0 0 0 4
New 144 37 1 0 0 0 4

December 2017 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 128 43 0 0 0 0 15
New 113 57 1 0 0 0 15

December 2018 – 25 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 293 46 2 0 0 0 0
New 270 68 3 0 0 0 0

December 2019 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 306 58 7 0 0 0 1
New 272 91 8 0 0 0 1

December 2020 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 259 81 1 0 0 0 31
New 221 118 2 0 0 0 31

December 2021 – 17 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 418 68 16 0 0 0 25
New 392 92 17 1 0 0 25

December 2022 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 409 120 19 0 0 0 10
New 359 169 20 0 0 0 10

December 2023 – 22 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 411 182 0 0 0 0 7
New 359 233 1 0 0 0 7