This indicator measures the number of days categorized as "unhealthy for sensitive groups." A day is categorized as "unhealthy for sensitive groups" when the Air Quality Index value measures above 100. This indicator is measured using data for Los Angeles County.

This indicator measures the median for Air Quality Index (AQI). AQI is measured each day for the County of Los Angeles. The indicator reflects the median of all 365 AQI collected for the year.