Processed on 2024-03-04 14:13:25 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 Washington 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 Washington

February 2014 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 754 16 0 0 0 0 14
New 712 58 0 0 0 0 14

February 2015 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 753 32 0 1 0 0 26
New 664 121 0 1 0 0 26

February 2016 – 112 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1006 70 2 1 0 0 23
New 894 182 2 1 0 0 23

February 2017 – 52 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1014 92 5 0 0 0 65
New 929 177 5 0 0 0 65

February 2018 – 130 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1253 26 0 0 0 0 37
New 1178 101 0 0 0 0 37

February 2019 – 67 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1283 181 3 0 0 0 45
New 1119 345 3 0 0 0 45

February 2020 – 129 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1604 90 1 0 0 0 16
New 1462 232 1 0 0 0 16

February 2021 – 71 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1587 75 3 0 0 0 43
New 1497 165 3 0 0 0 43

February 2022 – 83 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1598 200 3 2 0 0 17
New 1391 407 3 2 0 0 17

February 2023 – 106 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1773 138 1 1 0 0 47
New 1635 276 1 1 0 0 47