SALT LAKE CITY (KTVX) — On Friday, Feb. 4, Salt Lake City reached an air quality index score (AQI) of 154, which the state calls “unhealthy.” But what does that score really mean? According to an ...

Smoke from wildfires in Canada has drifted into the U.S., prompting air quality alerts for Americans as it continues to spread. But when officials and forecasters classify a city's air as "unhealthy" ...

Smoke from Canadian wildfires has impacted the air quality throughout United States, including in the northern High Plains, Midwest, Great Lakes, southern Mid-Atlantic and into the Northeast. This has ...

Here’s how to understand the Environmental Protection Agency’s Air quality index (AQI), which measures, on a 300-point scale (along with six categories and advisories), the quality of air in any given ...

This week, millions of Americans are anxiously scanning air quality maps focusing on two colors: red and purple. Red indicates "unhealthy" air quality, and purple? "Very unhealthy." When did purple ...

Delhi’s air quality plunged into the ‘very poor’ category on November 3, 2025, with AQI levels touching 316, making breathing ...

Delhi residents were confused by vastly different pollution readings on Tuesday. While India's CPCB showed AQI below 400, ...