Ozone Share of Pollution Days by County
Of the days when either ozone or fine particles drove the Air Quality Index, the share driven by ozone. Above 50% is a smog problem, made in sunlight and heat; below 50% is a soot problem, from smoke, wood and diesel. The two want different remedies.
See Ozone Share of Pollution Days on the interactive map →
Highest counties
| County | Ozone Share of Pollution Days |
|---|---|
| Gila County, Arizona | 99.7% |
| Yavapai County, Arizona | 99.7% |
| Albany County, Wyoming | 99.3% |
| White Pine County, Nevada | 99.2% |
| Coos County, New Hampshire | 99.2% |
| Rio Arriba County, New Mexico | 99.2% |
| Lee County, Florida | 99.1% |
| Denali Borough, Alaska | 98.9% |
| La Paz County, Arizona | 98.6% |
| El Dorado County, California | 98.6% |
| San Juan County, Utah | 98.6% |
| Lake County, California | 98.3% |
Lowest counties
| County | Ozone Share of Pollution Days |
|---|---|
| Contra Costa County, California | 3.3% |
| Alameda County, California | 3.8% |
| Hidalgo County, Texas | 5.6% |
| San Francisco County, California | 6.7% |
| Santa Clara County, California | 7.7% |
| Colusa County, California | 8.6% |
| Bayamón Municipio, Puerto Rico | 11.9% |
| Cameron County, Texas | 12.0% |
| Bibb County, Georgia | 12.8% |
| Marin County, California | 13.3% |
| Pulaski County, Arkansas | 15.0% |
| San Mateo County, California | 15.7% |