Improvement in Delhi's annual PM2.5 levels since 2015-17 halted in 2023, says CSE report

Delhi-NCR recorded the longest spell of ‘very poor’ or worse air quality and the maximum number of smog episodes in November and December 2023 in the last six years, according to a new analysis.

The Centre for Science and Environment (CSE), an independent think-tank that analysed pollution data for Delhi-NCR, said the gradual long-term improvement in annual PM2.5 levels since 201517 halted in 2023.

This occurred despite cleaner-than-usual summer and monsoon seasons and significantly reduced intrusion of smoke from farm fires in northern states. However, this winter witnessed unusually low surface wind speeds, trapping high levels of local pollution.