CASTNET sites provide air quality data in rural locations, often upwind or downwind of urban areas. Data provided by CASTNET include weekly concentrations of sulfur and nitrogen species, base cations, and chloride as well as hourly ozone. Some sites also provide other air pollutants (e.g., NO/NOy, CO) or meteorological data. Many CASTNET sites have been operating for more than 30 years, providing a long-term, consistent data record that is used to evaluate climate and regulatory impacts on air quality.
Use the data dashboard to access CASTNET data or download the available pre-packaged datasets using the link below.
See the Data Use and Citation page for recommended citations.