We recognize that many people have questions about the various air quality index (AQI) numbers available from different sources across Los Angeles. There are different methodologies used by various entities, and the varying methodologies may cause data to differ at specific points in time. Some factors that may impact data include, but are not limited to, the number of sites and the location from which air sensors draw, the types of pollutants they are measuring, the relative weight of these pollutants/components used in their calculation, and the way in which averages and/or aggregate data are calculated.

UCLA uses multiple sensors located on the campus to determine the AQI and utilizes the same NowCast methodology used by the U.S. Environmental Protection Agency (EPA) to inform our decision-making regarding campus operations. Please continue to check UCLA’s AirQual website to see air quality at UCLA. Additionally, we created a dedicated site that provides more explanation and detail on how campus air quality is measured and monitored.