Air Quality in India

How air quality works in India: the index it uses, the pollutants that dominate, the seasonal pattern, the cities to watch, and the agencies that monitor it. India reports on the National Air Quality Index.

The big picture

India has some of the most polluted air of any major country, with particulate matter the central problem — especially across the densely populated Indo-Gangetic Plain in the north. India reports air quality on its National Air Quality Index, a 0–500 scale whose categories are spaced very differently from the US AQI to reflect the country's much higher baseline exposure.

Dominant pollutants and where they come from

PM2.5 and PM10 dominate, from a stack of sources: vehicle exhaust, industry, coal-fired power, brick kilns, construction dust, biomass and solid-fuel cooking, road dust, and — seasonally — crop-residue burning. Ground-level ozone and NO₂ add to the urban mix.

The seasonal pattern

The summer monsoon (June–September) scrubs the air; the post-monsoon autumn and winter (October–February) are catastrophic across the north, when crop-residue burning, Diwali fireworks, and temperature inversions combine — see Delhi's Winter Smog and Stubble Burning. Southern and coastal cities fare better year-round.

Who monitors it

The Central Pollution Control Board (CPCB) runs the national network and AQI portal; SAFAR provides city forecasts and source apportionment; state pollution control boards operate regional monitors. The National Clean Air Programme sets reduction targets for the most polluted cities.

Cities in India

Primary sources: CPCB — National Air Quality Index · SAFAR (Ministry of Earth Sciences)