The Sacramento region’s air quality reached “unhealthy for sensitive groups” level on Thursday morning, according to IQAir.

After fires destroyed multiple neighborhoods across Los Angeles County, many residents looked up to find blue, smoke-free skies this week. The Air Quality Index (AQI) — which measures the ...

The AQI is measured on a scale from 0 to 500, with the lower the number, the healthier the air. (Getty Creative) But many Angelenos aren’t sure if the AQI tells the full story, especially given how ...

What is an Air Pollution Action Day? A Chicago area Air Pollution Action Day is declared when the ozone and/or particulate levels in the air are expected to be at or above the Unhealthy for Sensitive ...