An analysis of the Air Quality Index (AQI) for major Indian cities from 2015 to November 2025 shows Bengaluru has the cleanest air among metropolitan cities. But the city’s air quality is still not "safe," says the Climate Trends report. Climate Trends, a research and consulting group, found that none of India’s top cities have safe air quality. The report states, "AQI remains between 65 and 90 most years, although comparatively cleaner, these values still exceed the ‘Good’ category, but rapid urbanisation and vehicle growth prevent the city from falling into safe range," about Bengaluru. Delhi remains the most polluted city from 2015 to 2025. AQI peaked above 250 in 2016 and stays near 180 in 2025. The report notes, "While there is minor year-to-year fluctuation, the city never approaches safe thresholds and continues to experience chronic poor air quality driven by vehicular emissions, industrial activity, seasonal crop burning, and geographic factors." Some cities show slow improvement, but overall pollution remains high. Northern cities like Delhi, Lucknow, and Varanasi have the most severe and lasting pollution. Southern and western cities such as Chennai, Mumbai, Pune, and Bengaluru do better but still cannot reach truly healthy air-quality levels. The report highlights the ongoing effects of traffic, industry, seasonal factors, and fast urban growth across India. Palak Balyan, research lead at Climate Trends, said, "Moving to another city for cleaner air isn’t a real solution, and most people can’t afford to do it anyway. What India needs is sustained, long-term, science-based policy reform backed by genuine political will to take tough decisions." He added, "Air pollution affects everyone, but not equally: people who spend more time outdoors, like street vendors, sanitation staff, transport workers, and construction workers, are impacted the most."