The Air Quality Index (AQI) — which measures the concentration of pollutants in the air — seemed to confirm all was well in the L.A. atmosphere, with low numbers that suggested clean, healthy air.

The AQI chart is broken into six colors: green, yellow, orange, red, purple and maroon. Each color represents a range on the AQI chart from zero to 500, ...

The AQI chart is broken into six colors: green, yellow, orange, red, purple and maroon. Each color represents a range on the AQI chart from zero to 500, ...

As the AQI chart numbers gets higher, there are more warnings about ventilation and more restrictions on outdoor activities. Good : It’s fine to do normal activities and keep the windows open.

The AQI chart is used to classify air quality levels using a formula and the criteria pollutant numbers. A number is calculated daily unless there is an extreme condition, ...

The AQI chart is broken into six colors: green, yellow, orange, red, purple and maroon. Each color represents a range on the AQI chart from zero to 500, ...

The Air Quality Index chart is divided into six different colors. (Centers for Disease Control and Prevention) (Photo: Centers for Disease Control and Prevention) ...

The AQI chart is used to classify air quality levels using a formula and the criteria pollutant numbers. A number is calculated daily unless there is an extreme condition, ...

The AQI chart is used to classify air quality levels using a formula and the criteria pollutant numbers. A number is calculated daily unless there is an extreme condition, ...

The Air Quality Index chart is divided into six different colors. (Centers for Disease Control and Prevention) Lung-Wen Antony Chen , an associate professor in the Department of Environmental and ...

The AQI chart is used to classify air quality levels using a formula and the criteria pollutant numbers. A number is calculated daily unless there is an extreme condition, ...