Image data on daily and monthly total ozone.

U.S. Department of Energy's center for climate-change data and analysis. Includes climate variables, emissions data, and carbon cycling data.

Data from the EPA on major air pollutants and air quality monitoring. You can access national, regional, and local data for all measured pollutants which include particulate matter, nitrogen dioxide, and ground-level ozone.

Navigate to World Climate Data and Monitoring Programme to access extensive datasets on categories from aerosols to glaciology.

Real-time and historical sources of global atmospheric surface pressure in both daily and monthly increments.