WADOHThis feature layer shows the estimated peak ozone level for each 5 kilometer (km) grid cell from 2022-2024, measured in parts per billion (ppb). Higher ozone can lead to breathing problems. People most affected by higher ozone include children, older adults, people with asthma or other lung conditions, outdoor workers, and communities with fewer financial resources who may have fewer ways to avoid exposure. Concentrations are estimated by combining the National Oceanic and Atmospheric Administration (NOAA) forecast model with measured concentrations from the Washington Ambient Air Monitoring Network. The NOAA forecast model accounts for emissions, meteorology, and topography. The modeled and measured concentrations are combined to produce daily maximum 8-hour ozone concentrations. The 4th highest annual daily ozone concentration (as is defined by the EPA to be used to compare to the federal standard) is then calculated for all points in the grid. Its important to note that ozone can vary within smaller areas and might not reflect the true air quality community members experience. This layer was created by the Department of Ecology to support the Washington Tracking Network and the Environmental Health Disparities (EHD) Map. Citation Washington Tracking Network, Washington State Department of Health. Web. "Ozone Concentration". Data obtained from the Department of Ecology, 2022-2024 Data. Published September 2025. Contact us at EHDMap@doh.wa.gov if you have questions or comments.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/74a0af591b6d4af687e014e9fdf62459_0engState of Washington Geospatial Open Data PortalPublicOzone Peak Annual Concentration [Washington (State)]Web servicesWashington (State)Last Modified: 2026-01-15