Processed on 2024-03-04 13:55:09 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 Oregon 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 Oregon

December 2014 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 563 131 0 0 0 0 19
New 455 239 0 0 0 0 19

December 2015 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 545 100 0 0 0 0 6
New 473 172 0 0 0 0 6

December 2016 – 70 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 511 206 1 1 0 0 25
New 384 333 1 1 0 0 25

December 2017 – 32 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 434 278 18 0 0 0 45
New 310 401 18 1 0 0 45

December 2018 – 78 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 609 195 2 0 0 0 31
New 463 341 2 0 0 0 31

December 2019 – 37 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 543 298 6 1 0 0 20
New 386 455 6 1 0 0 20

December 2020 – 106 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1273 388 3 0 0 0 41
New 992 669 3 0 0 0 41

December 2021 – 67 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1883 114 0 0 0 0 18
New 1713 284 0 0 0 0 18

December 2022 – 72 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1675 347 3 2 0 0 81
New 1455 566 4 2 0 0 81

December 2023 – 79 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1721 249 6 0 0 0 124
New 1512 458 6 0 0 0 124