5-3-1 Visibility Method
More Info on Washington's Air Monitoring Network
Note: Some users might notice small differences in colors shown on the map on this website, and those reported on the state's air monitoring network. The map on this website uses the national air quality reporting system called the Air Quality Index (AQI) for calculating the air quality health category. However, the state uses the Washington Air Quality Advisory (WAQA) system of calculating air quality. Both use color-coded categories to show when air quality is good, moderate, or unhealthy. The difference is that the state's WAQA is based on lower levels of fine particle pollution than the federal AQI, providing an earlier alert of potential air quality risks. If in doubt as to which better represents public health risk, use the more stringent of the two (i.e. the map showing worse air quality). See the WAQA color guidance, also en Español.
For Frequently Asked Questions (FAQs) about Washington’s air monitoring network follow these steps once you are on the state’s air monitoring page: