Processed on 2024-03-04 14:05:10 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 Tennessee 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 Tennessee

December 2014 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 140 41 0 0 0 0 5
New 80 101 0 0 0 0 5

December 2015 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 149 32 0 0 0 0 5
New 106 75 0 0 0 0 5

December 2016 – 13 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 73 51 44 9 0 0 9
New 59 64 45 9 0 0 9

December 2017 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 151 35 0 0 0 0 0
New 114 72 0 0 0 0 0

December 2018 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 226 14 0 0 0 0 8
New 190 50 0 0 0 0 8

December 2019 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 223 21 0 0 0 0 4
New 188 56 0 0 0 0 4

December 2020 – 16 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 194 48 0 0 0 0 6
New 150 92 0 0 0 0 6

December 2021 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 215 57 0 0 0 0 7
New 171 101 0 0 0 0 7

December 2022 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 243 32 0 0 0 0 4
New 209 66 0 0 0 0 4

December 2023 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 260 37 0 0 0 0 3
New 225 72 0 0 0 0 3