Cities in California, Texas and Arizona are expecting air quality to become unhealthy for sensitive groups on Thursday.

The map pulls data from air monitors, hundreds of pollution sensors, and forecast models to provide real-time air quality index (AQI) readings for more than 1,000 locations. Los Angeles’ air ...

The Air Quality Index (AQI) is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. For more ...