Air pollution in Indian capital cities during Diwali was worse than the previous year, with Patna recording the highest average level of particulate matter 2.5 (PM2.5), 13 times higher than the safe limit set by the WHO. Analysis of data from monitoring stations in 11 capital cities found that eight cities had lower PM2.5 levels compared to the previous year, while Gandhinagar, Kolkata, and Patna had higher levels. Delhi recorded the highest average PM2.5 levels the day after Diwali. Bengaluru had lower PM2.5 levels this year compared to last, but widespread firecracker use reversed the gains made due to rainfall.