In brief
Swiss air‑quality tracker IQAir ranked Delhi highest in the world with a US Air Quality Index of 581 on the eve of Diwali, prompting the Indian government to order online schooling and encourage work‑from‑home. Independent Indian monitors also recorded a “very poor” rating at 363. Delhi’s bad air‑quality forecast marks the worst pre‑Diwali levels in eight years and is amplified by the planned fireworks of the holiday.
On the morning of November 7, IQAir listed Delhi as the most polluted major city in the world, scoring a US Air Quality Index of 581 – double the 285 score for Lahore. The spike comes just before Diwali, the Hindu festival of lights. The Indian government ordered schools in and around Delhi to shift to online classes and urged people to work from home, warning that the festival’s widespread use of firecrackers would worsen the air.
At the same time, India’s Central Pollution Control Board reported a separate index of 363 at 10 a.m., putting Delhi in the “very poor” category. Local media said the city’s Friday air quality was the worst pre‑Diwali air in eight years, highlighting the “closed‑atmosphere” winter conditions that trap pollutant‑laden air over the region.
While IQAir uses concentrations of particulate matter to calculate its score, India’s official scale differs in methodology, meaning numbers are not directly comparable. The Swiss organization, based in Geneva, has long noted that Delhi repeatedly tops their global list every winter.
In a rare bright spot, the Air Quality Early Warning System announced that Delhi’s 24‑hour average Air Quality Index dropped to 218 on Diwali day, its best reading in eight years. But that improvement came after the fireworks and post‑holiday cleanup, not before the festival’s peak pollution buildup.
These combined numbers underscore the heavy health burden Delhi faces each winter, as the city contends with vehicle emissions, construction dust, crop‑waste burning and nearly a hundred thousand fireworks per day for Diwali celebrations.
