Alireza

@olafveerman The numbers in the charts you posted are an index number, which I guess means they don't have a unit. There is a map on the Farsi homepage which...

This is the unit of the numbers: https://en.wikipedia.org/wiki/Air_quality_index 

We can also contact the people in charge of the site and ask them about how they are calculating the AQI or if there is a way to get the...