Not Delhi, Bangalore, Mumbai, this city is most polluted in October, cleanest city is…

Delhi ranked sixth most polluted city in October

Although Delhi is considered the most polluted city in India, and every year courts and governments debate stubble burning and vehicle emissions as the main source, surprisingly, it is not the most polluted city, at least in October 2025. The latest study by the Center for Research on Energy and Clean Air (CREA) revealed that Delhi was ranked as the sixth most polluted city in India in October 2025, ahead of neighboring cities such as Ghaziabad and Noida.

Which is the most polluted city?

CREA’s study included factors such as continuous ambient air quality monitoring data that indicate an alarming decline in air quality across the country; The Indo-Gangetic Plain, especially the National Capital Region (NCR), witnessed the sharpest declines. Among the most polluted cities, Haryana’s Dharuhera in October 2025 ranked first with an alarming average PM2.5 concentration of 123 g/m2, greatly exceeding the National Ambient Air Quality Standard (NAAQS) on nearly 77% of the days.

The city experienced two ‘Severe’ and nine ‘Very Poor’ days for air quality, revealing a persistent pollution crisis. During the same period, Delhi’s monthly average PM2.5 level remained at 107 g/m2; this was almost three times the September average of 36 g/m2; This underlines a continuous, rapid and shocking increase in air pollution.

Other The 10 most polluted cities?

According to official data, stubble burning contributed to less than 6 per cent of Delhi PM in October, but the huge increase in pollution last month was a result of sources of emissions throughout the year; This shows that the impact of short-term seasonal measures such as the Gradual Response Action Plan (GRAP) is limited. This also suggests that the government must opt ​​for strong, long-term mitigation strategies to tackle emissions from vehicles, industries and construction activities.

Other cities around Delhi such as Rohtak, Ghaziabad, Noida, Ballabgarh, Bhiwadi, Greater Noida, Hapur and Gurgaon, most parts of the NCR region and neighboring states of Haryana and Uttar Pradesh were also included in the 10 most polluted cities.

On the other hand, Meghalaya’s capital Shillong was ranked as the cleanest city with an average PM2.5 concentration of just 10 g/m2. Karnataka and Tamil Nadu were also among the cleanest cities. However, while 212 out of 249 cities recorded PM2.5 levels, this too is within India’s NAAQS limit of 60 g/m2; only six cities met the World Health Organization’s safe daily guideline of 15 g/m2.