What is Air Quality?

Texas is known for its wide, open skies and bright summer days. However, hot weather and pollutants from cars, trucks, and factories can cause our air to become dirty and unhealthy, especially for Texans who are sensitive to air pollution. The two main things that can cause the air to become unhealthy are ozone and particulate matter.

What is Ozone?
Ozone is a gas that forms when three oxygen molecules bond together. It performs a very important job in our upper atmosphere by protecting the earth from the sun’s harmful rays. This blanket of ozone is called the ozone layer. However, when ozone is in our lower atmosphere, where we breathe air, it can be harmful to humans.

What is Particulate Matter (PM)?
Particulate matter is a mixture of small particles and water droplets in the air. When it is present in large amounts, it can mix with ozone and other dangerous pollutants to become smog. This is unhealthy for people to breathe, especially if they have asthma or other health conditions that might make them sensitive to air pollution.

How Do We Measure Air Quality?
Scientists are able to measure air quality and let us know when it is safe to play outside. By tracking the amounts of ozone and particulate matter, we can determine how clean or dirty our air is. To make it easy to understand, scientists created a color chart. This chart is called the Air Quality Index (AQI). The colors move from green to purple, with green being healthy, clean air and purple being very unhealthy air.




sky aqi


If you want to learn more about the current and future air quality in your area, visit the TCEQ Air Quality Forecast webpage.


Check out your lifetime impact on the environment and learn how you can make a difference.

Do your part

Do Your Part

Take The Pledge

Take th e Pledge and we will send you a FREE Texas Parks & Wildlife "Texas State Parks: Official Guide" and a FREE sticker!

state park and sticker

News You Can Use Newsletter

Do your part

Take Care of Texas License Plate

Order Your Plate

License Plate