US counties by share of days unhealthy for sensitive groups or worse (US EPA AQI), 2009
Kern County 46.3%, the highest of 1052 counties, 2009
- Under 0.3
- 0.3 to 0.8
- 0.8 to 1.6
- 1.6 and over
- No data
Boundaries: U.S. Census Bureau cartographic boundary files.