Please note that the Air Pollutant Index reported by the DoE is calculated based on the 24 hours running average of the most dominant pollutants (including PM2.5, PM10 and Ozone). This can make it really difficult to find out what the actual air quality is in real time. The best practice is to report real-time air quality using hourly data, which is what most EPA worldwide do.
For instance, during a period of Haze, where the Air Quality Index can deteriorate significantly and fast, the published Air Pollution index is most likely lower than the actual pollution. Similarly, when the air polution decreases, the Air Quality Index can still be very high although the pollution is gone.Read more here.
Usage Notice: All the Air Quality data are unvalidated at the time of publication, and due to quality assurance these data may be amended, without notice, at any time. The World Air Quality Index project has exercised all reasonable skill and care in compiling the contents of this information and under no circumstances will the World Air Quality Index project team or its agents be liable in contract, tort or otherwise for any loss, injury or damage arising directly or indirectly from the supply of this data.
The Data sources used for the Air Quality, Air Pollution, PM25 (fine particulate matter), PM10 (respirable particulate matter), NO2 (nitrogen dioxide), SO2 (sulfur dioxide), CO (carbon monoxide), O3 (ozone) and Weather data in this page are coming from: