Annual Ozone Air Quality

This indicator gives a grade to each county in the U.S. based on the annual number of high ozone days. The American Lung Association (ALA) assigns grades A-F to counties (A=1; B=2; C=3; D=4; F=5), based on average annual number of days that ozone levels exceeded U.S. standards during the three year measurement period. The five-point grading scale was used for the distribution (Green = <2; Yellow = 2 - 3; Red = >3). The air quality data is collected by the EPA and summarized by the ALA.

  • Measurement Period: 2018-2020
Annual Ozone Air Quality
RANGE: 1<5

Understanding the color Range

Each Health Indicator includes five-color range indexes. The color range index compares all counties in the state that have the same indicator in the same timeframe. It then calculates where the selected county falls in that range and displays the color that best reflects how the county is doing in comparison to the other counties in the filtered group. The range displays the highest and lowest county values within the state that have the same indicator for the same measurement period.

Current county values will be compared to State and National values if they are available.

Green and red arrows indicate that the county value is better or worse than the state or national value. The arrows will change directions and colors based on which end of the range is positive.
This icon simply means that the county value is equal to the state or national value.
Some indicators display blue, which means the data is not meant for health-status comparison, but is intended simply to provide information.
If history data is available the trend icon will point up or down based on its relationship to the last county value.
Dimensions 2018-2020
Dimension Low Value High Number of Counties Compared
CDC Treatment Guidelines
American Lung Association