Diwali firecrackers triggered overnight pollution spikes in Mumbai, with Navy Nagar recording an AQI of 497 and several areas crossing 400. Mumbai recorded a better Diwali AQI of 132 than last year, but evening firecrackers pushed PM2.5 levels to over 600 in parts of the city. Mumbai's Diwali air was cleaner than last year, but firecrackers pushed PM2.5 levels sharply higher by evening, with smog across several areas.