This article originally appeared on Cincinnati Enquirer: Air quality alert in Cincinnati, then heat index reaching 103 degrees. What to know Temperatures are climbing into the 90s and heat index ...

After nearly two days under an Air Quality Warning issued by Environment and Climate Change Canada, we're taking a look at ...

The EPA's Air Quality Index can tell you whether breathing outside air can be harmful. Here's how to read the scale to plan ...

AirNow and PurpleAir use the Air Quality Index, or A.Q.I., a measure of air quality from 0 to 500 that is composed of six categories, from “good” to “hazardous.” ...

The EPA's AQI ranges from 0 to 500 and represents the measurement of these five different major pollutants regulated by the Clean Air Act.

The National Weather Service has issued both a heat and air quality alert for most of downstate New York, Wednesday, July 16.

Unhealthy Air Quality Index level. Red: Indexes in the 151 to 200 range are considered "unhealthy." At this level, any member of the general public becomes susceptible to health effects.