Ghaziabad emerges as India’s most polluted city in winter 2025–26, while no city meets WHO air quality guidelines.
Centre for Research on Energy and Clean Air’s (CREA)new winter air quality analysis has revealed a worsening pollution trend across India, with 204 out of 238 cities recording average PM2.5 concentrations above the country’s National Ambient Air Quality Standards (NAAQS) during the winter of 2025–26.
The study, based on data from Central Pollution Control Board (CPCB) reveals Continuous Ambient Air Quality Monitoring Stations between October 1, 2025, and February 28, 2026, found that the number of cities exceeding the national PM2.5 limit of 40 μg/m³ rose from 173 in winter 2024–25 to 204 this winter. None of the analysed cities met the World Health Organization guideline of 5 μg/m³ for PM2.5, highlighting persistent and widespread air quality challenges.
Among cities covered under the National Clean Air Programme (NCAP), 84 out of 96 with sufficient monitoring data recorded winter PM2.5 levels above India’s national standard, while all 96 exceeded the WHO guideline. Similarly, in non-NCAP cities, 120 out of 142 breached the national limit and every city exceeded the WHO threshold.
Air pollution remained particularly severe across the Indo-Gangetic Plain, where 75 out of 79 monitored cities surpassed the national PM2.5 standard. In the National Capital Region, none of the 28 cities with sufficient data met the national air quality limit.
The report identified Ghaziabad as the most polluted city during winter 2025–26 with an average PM2.5 concentration of 172 μg/m³, followed by Noida at 166 μg/m³ and Delhi at 163 μg/m³. Delhi experienced 18 ‘Severe’ pollution days, 87 ‘Very Poor’ days, and only one ‘Good’ air quality day during the winter period.
Other cities among the top ten most polluted included Greater Noida, Bahadurgarh, Dharuhera, Gurgaon, Bhiwadi, Charkhi Dadri and Baghpat. Uttar Pradesh and Haryana accounted for four cities each in the top ten list.
At the state level, Haryana recorded the highest number of cities where all monitored locations exceeded the PM2.5 standard, followed by Andhra Pradesh, Punjab, West Bengal and Gujarat. Several other states including Rajasthan, Maharashtra, Bihar, Uttar Pradesh, Odisha and Madhya Pradesh also recorded high proportions of cities breaching the national standard.
In contrast, Chamarajanagar emerged as the cleanest city in the country during winter 2025–26, with an average PM2.5 concentration of 19 μg/m³. Eight of the ten cleanest cities were located in Karnataka.
Among India’s megacities, Kolkata, Mumbai and Chennai also recorded winter PM2.5 levels above the national standard, while Bengaluru remained slightly below the limit with an average concentration of 39 μg/m³.
According to CREA’s India Analyst Manoj Kumar, the comparison between the last two winters shows continued widespread non-compliance. He emphasized the need for nationwide PM2.5 reduction targets and stronger action to control gaseous pollutants such as sulphur dioxide, nitrogen dioxide and volatile organic compounds, which contribute to the formation of secondary particulate matter and ozone pollution.