The Air Quality Index (AQI) tells you how clean or polluted your outdoor air is and the associated health effects that may be of concern.

The U.S. Air Quality Index (AQI) is EPA's tool for communicating about outdoor air quality and health. The AQI includes six color-coded categories, each corresponding to a range of index values. The higher the AQI value, the greater the level of …

AirNow is your one-stop source for air quality data. Our recently redesigned site highlights air quality in your local area first, while still providing air quality information at state, national, and world views.

What it is: The U.S. Air Quality Index, or AQI, is EPA’s tool for communicating daily air quality. It uses color-coded categories and provides statements for each category that tell you about air quality in your area, which groups of people may be affected, and steps you can take to reduce your exposure to air pollution.

The list below shows the areas with the highest NowCast AQI for the current hour. The AirNow system automatically generates this list every hour, based on the areas with the highest NowCast AQI for ozone or particle pollution.

Local air quality can affect our daily lives. Like the weather, it can change from day to day. EPA developed the Air Quality Index, or AQI, to make information available about the health effects of the five most common air pollutants, and how to avoid those effects.

¿Cómo funciona el AQI? El Índice de Calidad del Aire de EE. UU. (AQI, por sus siglas en inglés) es una herramienta de la EPA para informar sobre la calidad del aire exterior y la salud. El AQI incluye seis categorías codificadas por colores, cada una corresponde a …

effort is the Air Quality Index, or AQI. EPA and local offi-cials use the AQI to provide simple information about your local air quality, how unhealthy air may affect you, and how you can protect your health. What is the AQI? The AQI is an index for reporting daily air quality. It tells you how clean or unhealthy your air is, and what associ-

Smoke from several wildfires in the Los Angeles, California area is affecting air quality in portions of the state. Check the AirNow Fire and Smoke Map for local air quality conditions, fire locations and smoke plumes.

The Air Quality Index uses numbers from 0 to 500. These numbers are used to decide the AQI color. On days measuring less than 100, the air is clean. If the air is dirtier, the numbers get bigger. On days measuring more than 100, the air can be bad for you to breathe. Here is how the AQI numbers match up with the AQI colors: