California Air Resources Board California map with basin borders
California Air Basins  

California is divided geographically into air basins for the purpose of managing the air resources of the State on a regional basis.  Areas within each air basin are considered to share the same air masses and are therefore expected to have similar ambient air quality.  The State is currently divided into 15 air basins.  The names of the basins are listed below on the State map or in the air basins directory list.  To obtain summary information on the air basin of interest to you, click on the name or basin.

California map

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This page last revised on April 5, 1997

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