Processed on 2024-03-04 13:53:41 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 April.

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.

April in Oregon

April 2014 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 622 6 0 0 0 0 23
New 608 20 0 0 0 0 23

April 2015 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 575 14 0 0 0 0 31
New 558 31 0 0 0 0 31

April 2016 – 70 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 639 2 0 0 0 0 41
New 630 11 0 0 0 0 41

April 2017 – 32 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 674 3 0 0 0 0 36
New 666 11 0 0 0 0 36

April 2018 – 78 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 654 6 1 0 0 0 52
New 645 15 1 0 0 0 52

April 2019 – 37 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 777 3 0 0 0 0 57
New 769 11 0 0 0 0 57

April 2020 – 106 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 835 3 0 0 0 0 123
New 820 18 0 0 0 0 123

April 2021 – 67 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1573 25 1 0 0 0 168
New 1519 79 1 0 0 0 168

April 2022 – 72 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1879 5 0 0 0 0 100
New 1861 23 0 0 0 0 100

April 2023 – 79 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1918 8 1 0 0 0 119
New 1904 22 1 0 0 0 119