How to read the Air Quality Index (AQI) scale, and how it can help you stay safe from wildfire smoke
This article explains the Air Quality Index (AQI) scale, detailing how it measures air pollution levels and helps individuals protect themselves from health risks, particularly from wildfire smoke. It highlights recent Canadian wildfires impacting air quality in parts of the United States, including New York City and Detroit.
Why it matters
Understanding the AQI is crucial for public health and safety, enabling individuals to take necessary precautions during environmental events like wildfires that significantly worsen air quality.
Smoke from wildfires in Canada shrouded the Manhattan skyline on July 15, 2026. Bloomberg/Getty Images Wildfires are raging across Canada , and the smoke is being pushed southward. The air quality began decreasing on Wednesday and continued into Thursday. Here's a guide to understanding the Air Quality Index (AQI), a metric used to assess air quality. As more than 800 wildfires burn across Canada, including dozens of out-of-control fires in western Ontario, the resulting smoke has worsened air quality in various parts of the United States, including the Great Lakes, the Midwest, and the Northeast. Unsettling images of orange skies in New York City on Wednesday and Thursday raised widespread concern and confusion about the risks posed by poor air quality. To determine the quality of the air, the Environmental Protection Agency (EPA) uses the Air Quality Index , or AQI. The scale spans from 0 to 500.
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