US counties by share of days unhealthy for sensitive groups or worse (US EPA AQI), 2013
Fresno County 38.1%, the highest of 1020 counties, 2013
- Under 0.3
- 0.3 to 0.6
- 0.6 to 1.4
- 1.4 and over
- No data
Boundaries: U.S. Census Bureau cartographic boundary files.