What AQI is on an Apple Watch, and how it’s measured

Your Apple Watch includes a complication called AQI, which reports on the Air Quality Index for your location.

It’s easy to add this complication to many watch faces, so you can keep tabs on the local air quality with just a glance.

Check out the products mentioned in this article:

Apple Watch Series 5 (From $399 at Best Buy)

What AQI is on an Apple Watch, and how it’s measured

The Air Quality Index is a standard way of reporting air quality used by many government agencies, such as the Environmental Protection Agency in the US. It’s a numeric scale that goes from 0 to 500, in which the lower the number, the better the air quality.

The EPA calculates the AQI based on five major air pollutants: ozone, particulates, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

Here are the major AQI categories according to the EPA:

• 0 to 50. Air quality is considered “good,” and air pollution posts “little or no risk.” This is color coded green.

• 51 to 100. Air quality is “moderate,” and “there may be a moderate health concern for a very small number of people.” This is color coded yellow.
• 101 to 150. This range is “unhealthy for sensitive groups.” The EPA says that individuals with lung disease, older adults, and children may be at a greater risk from exposure to ozone. Persons with heart and lung disease may be at greater risk from the presence of particles in the air. This is color coded orange.
• 151 to 200. This is “unhealthy,” and everyone may experience adverse health effects. This is color coded red.
• 201 to 300. “Very unhealthy.” This level would trigger a health alert. This is color coded purple.
• 301 to 500. The EPA calls this “hazardous,” and considers this level an emergency. It is color coded maroon.

How to use the AQI complication on your Apple Watch

If you choose a watch face with the AQI complication, you can see the AQI number at a glance.

To get more information, tap the complication, and you’ll see the AQI, the description (such as “Good” or “Moderate”) and where your AQI falls on a color scale from green to maroon.

For information on how to add an AQI complication to your watch, read our article, “ How to add app complications to your Apple Watch, and customize them for optimal use.”