Air Quality index is available only for some US, Canda and all Europe and UK cities.
The AQI is an index for reporting daily air quality. It tells you how clean or unhealthy your air is, and what associated health effects might be a concern. The AQI focuses on health effects you may experience within a few hours or days after breathing unhealthy air. The AQI is calculated for few major air pollutants: ground level ozone, particle pollution, carbon monoxide, sulfur dioxide etc. Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little or no potential to affect health, while an AQI value over 300 represents air quality so hazardous that everyone may experience serious effects.
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