Each Air Quality Index category, also known as the level of concern, is attached to a certain range of values: Good (green): 0 to 50; Moderate (yellow): 51 to 100; ...

Early in the morning, Google’s air quality map showed that Chicago had the worst air in the country. Apple’s weather app, too, showed that the Air Quality Index had climbed into the 400s, a ...

The Air Quality Index (AQI) is used by various government agencies to report how clean or polluted the air is in your area. For example, you may have spotted this metric popping up in local ...

The national average air quality index in 2023 was 38, according to IQAir, a Swiss air quality technology company. More than 100 nations had cleaner air , on average, than the United States, and ...

Air quality in the U.S. is measured by the Environmental Protection Agency (EPA) using an air quality index (AQI), which rates air quality on a scale of zero to 500.

The Air Quality Index does not take into account many gas or particle contaminants that are produced during wildfires, particularly when houses, cars and other man-made materials go up in flames.

Users across Chicago were met with warnings from their smartphones about the city's air quality Wednesday that led to much confusion, but was the air quality actually that bad?

The Air Quality Index, or AQI, is the primary system used to warn the public when air pollution is dangerous. It’s based on data collected from 5,000 air monitors across the country.