Trends Summary: Select Pollutant, Year Range, & Area

Step 1: Select a Pollutant
Step 2: Select a First Year
 OR Select All Years
Step 3: Select a Summary Type¹ Summarize by Site
Summarize by County
Summarize by Air Basin
Summarize by 8-Hour Ozone Planning Area
Step 4: Select a County²
 OR an Air Basin²
 OR an 8-Hr Ozone Plan Area²
 OR Statewide²
Step 5: Submit Your Selections



The Trends Summary displays all available years from the First Year (as selected in Step 2 above) through 2021.


If you choose to summarize by site, you may choose to have iADAM list the monitoring sites within one of California's counties, within an air basin, within an 8-hour ozone planning area, or within the state.

Air Basins are multi-county regions of the state that have similar meteorological and geographic conditions. Air basins boundaries typically follow county boundaries, but there are several instances within the state where air basin boundaries fall within a county, dividing the county between two or more air basins.

8-Hour Ozone Planning Areas are regions of the state that the U.S. Environmental Protection Agency has defined for the purpose of planning for the attainment of a national 8-hour ozone ambient air quality standard. These planning areas include many geographical configurations, including multiple counties, single counties, or portions of counties.