Guwahati: Most cities in the Northeast have performed poorly in the Swachh Vayu Sarvekshan 2026, with Kohima and Dimapur placed in the lower half of the national ranking among cities with populations below three lakh.

The report was released by the Union Ministry of Environment, Forest and Climate Change (MoEFCC) in connection with Swachh Vayu Diwas, observed on the occasion of the International Day of Clean Air for Blue Skies.

The MoEFCC also awarded the best-performing cities and wards under the National Clean Air Programme (NCAP), based on the fifth Swachh Vayu Sarvekshan.

The Swachh Vayu Sarvekshan framework, released in 2022-23, assesses measures taken by cities on road dust, solid waste management, vehicular emissions, industrial pollution, construction and demolition waste, other emissions such as DG sets and commercial establishments, and information, education and communication (IEC) activities.

The assessment covers 130 cities across three population categories — below three lakh, three to 10 lakh, and above 10 lakh. The process involves city-level self-assessment, approval by State-level Monitoring Committees, evaluation by the Central Pollution Control Board (CPCB), field verification by independent committees and selection of the best-performing cities.

Among cities with populations between three lakh and 10 lakh, Guwahati was the best-performing Northeast city, ranking 15th with a score of 179.6.

In the below-three-lakh category, Dimapur ranked 34th with a score of 146.5, while Kohima stood 36th with 134.1.

Other Northeast cities in the category recorded mixed results. Silchar ranked 20th with 178.7, Sivasagar 25th with 168.5 and Nagaon 33rd with 152.3. Byrnihat was ranked 38th with 108.5.

Nagaland, however, had some representation among the state-level ward awardees. Kohima Municipal Council’s Ward 16 was listed in Category II, while Dimapur Municipal Council’s Ward 15 and Kohima’s Ward 10 featured in Category III.

The rankings offer a mixed picture for the Northeast. While individual wards have secured recognition, the relatively low scores of several cities underline the need for stronger and sustained action on road dust, waste management, vehicular emissions and other urban sources of air pollution.

Editorial note: Guwahati’s seasonal air-quality challenge

Guwahati’s relatively strong performance in the Swachh Vayu Sarvekshan — where it ranked 15th among cities with populations between three lakh and 10 lakh comes against the backdrop of a persistent seasonal air-quality challenge.

From November onwards, reduced rainfall, heavily polluted haze, dust generated by construction and infrastructure works, shrinking green cover, wetlands and emissions from industries around the city combine to worsen air quality. Pollutants transported from the eastern Indo-Gangetic plains to the Brahmaputra Valley can further aggravate the situation as the monsoon weakens.

The deterioration has become pronounced enough for residents to refer to Guwahati as Dhulihati (city of dust). Over the past several years, the city has repeatedly recorded elevated PM2.5 and PM10 levels during winter, at times approaching three times the national safe limits.

The wider regional pattern also points to the limitations of viewing urban air pollution solely as a city-level problem. Satellite-based studies have indicated that pollution across the Brahmaputra Valley and the wider Northeast is shaped by interconnected and shifting airsheds, making it a broader transboundary challenge rather than an issue confined to individual cities.

In this context, Guwahati’s 15th-place position reflects the measures assessed under the Swachh Vayu framework, but does not necessarily capture the full seasonal and regional dynamics that influence the city’s air quality.