Processed on 2024-03-04 14:13:34 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 March.

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.

March in Washington

March 2014 – 30 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 890 4 0 0 0 0 5
New 873 21 0 0 0 0 5

March 2015 – 41 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 825 37 0 0 0 0 37
New 750 112 0 0 0 0 37

March 2016 – 112 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1131 3 0 0 0 0 13
New 1106 28 0 0 0 0 13

March 2017 – 52 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1282 5 0 0 0 0 15
New 1250 37 0 0 0 0 15

March 2018 – 130 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1408 8 0 0 0 0 41
New 1367 49 0 0 0 0 41

March 2019 – 67 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1479 137 5 0 0 0 53
New 1294 322 5 0 0 0 53

March 2020 – 129 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1739 83 0 0 0 0 38
New 1633 189 0 0 0 0 38

March 2021 – 71 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1761 100 3 0 0 0 89
New 1607 254 3 0 0 0 89

March 2022 – 83 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1836 56 0 0 0 0 30
New 1755 137 0 0 0 0 30

March 2023 – 106 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2110 45 0 0 0 0 46
New 2019 136 0 0 0 0 46