Delhi ranked world's most polluted major city by IQAir a day before Diwali

Delhi was the world's most polluted major city on Saturday morning, 7 November 2026, according to a ranking by Swiss group IQAir. Reuters and the South China Morning Post (SCMP) both reported the ranking.

The Indian capital faced severe pollution forecasts a day before Diwali, the Hindu festival of lights.

Both outlets attribute the ranking to IQAir, so it rests on one underlying origin.

What is reported

According to SCMP, IQAir ranked Delhi first among the world's major cities at 10.35am, with a US air quality index reading of 581. SCMP reported that Lahore, in neighbouring Pakistan, had a reading of 285 in the same ranking. It described Delhi's reading as double that of Lahore.

India ordered schools in and around Delhi to offer online classes ahead of Diwali, according to SCMP. The outlet also reported that India encouraged people to work from home.

According to SCMP, Diwali falls on Sunday and is usually marked by the widespread use of firecrackers, which further worsen air quality.

What each side says

Doctors said residents should wear N95 masks and scrap morning runs, according to SCMP. They also said firecrackers will worsen the toxic air. The reports do not identify the doctors or say whether they represent an organisation.

What the reports do not say

The reports reviewed by Vocemundi do not name the Indian authorities behind the school and work-from-home measures. They do not say how long those measures will last.

The reports do not identify who issued the severe pollution forecasts or give their specific figures. They also do not describe any official Indian air quality readings that could be compared with IQAir's figures.

IQAir's ranking method is not explained in the reports, nor is the way it decides which cities count as major. The time zone for the 10.35am ranking is not stated.

The reports do not specify the pollutants involved. Beyond the expected contribution of firecrackers during Diwali, they do not describe the causes of the current pollution. They also do not say whether any firecracker restrictions are in place for this Diwali.

Analysis

The ranking is a snapshot of one morning, not a measure of a longer trend. Its significance depends partly on IQAir's method, which the reports do not explain. Official Indian readings, if compared, could help show whether other measurements point the same way. If firecrackers are used widely on Sunday, as is usual, air quality could worsen, as the doctors cited expect. Weather and other factors the reports do not address could also affect conditions. The coming days may show how much online classes and home working reduce public exposure, though the reports do not say how long these measures will last.

Produced by the Vocemundi newsroom with AI assistance.