No major Indian city has achieved a safe Air Quality Index (AQI) level in the past decade (2015-November 20, 2025), with New Delhi remaining one of the worst performers, a study of annual average AQI of 11 Indian cities showed.
The study highlighted that meteorology and geography are contributing to the persistent winter smog, especially in the Indo-Gangetic region.
A study by Climate Trends pointed out that cities such as Kolkata, Mumbai, Chennai, Chandigarh, and Visakhapatnam experienced moderate but still unsafe AQI levels in the past decade.
While Bengaluru had the cleanest air among metros, its average AQI remained above the ‘good’ category.
AQI in some cities improved after 2020, but none came close to achieving healthy air quality. With an AQI around 180 in 2025, Delhi remained the most polluted city throughout the decade.
In North and West India, cities such as Lucknow, Varanasi, and Ahmedabad consistently recorded high, unhealthy AQI levels.
According to the study, a major drop in farm fires did not improve Delhi’s air quality this year, underscoring that local pollution sources combined with meteorology are driving severe winter smog in the national capital.
“The absence of big rainfall events in October and weak western disturbances eliminated natural pollutant washout, accelerating early smog formation.”
Climate Trends said that the decade-long dataset underscores how India’s air pollution issue remains national, persistent, and structural, driven by urbanisation, traffic, industry, and seasonal factors — demanding systemic and science-based policy efforts.
It added that even improving cities remain outside the safe AQI range.
It said that despite recent policy interventions and technological improvements, top Indian cities continue to face serious air quality challenges, highlighting the need for more aggressive pollution-control strategies, sustained enforcement measures, and long-term urban planning reforms.
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