Mumbai’s air has not been ‘safe’ to breathe since 2015

The AQI assessment carried out by the environment think tank Climate Trends shows that Mumbai’s average AQI readings between 2015 and 2025 (November 20) stand between 80 and 120, which is usually the moderate range. Further, the study also shows that in 2022, the average AQI readings reached 120 which is the worst reading in the decade, followed by 119 in 2023, 112 reported in 2018 and 2021.

Mumbai usually records heavy rains between June and October due to which the city’s AQI usually stays in the ‘satisfactory’ or ‘safe’ category during these four months. Following the monsoon withdrawal, Mumbai’s overall AQI plummets and it again improves in the months of March due to wind reversal.

Meanwhile, experts attributed that for a coastal city like Mumbai, recording an average AQI readings for moderate category is a case of concern.

“Being a coastal city, Mumbai has the advantage of periodic wind reversal. The city also has an advantage of the prolonged monsoon season due to which the atmosphere stays relatively clean for four months as rains clear away the pollutants. Therefore, recording an average AQI over 100 all throughout the year is a case of concern since it indicates that during the winter season when the winds usually get slower the AQI would have been much worse,” said Akshay Yadav, an atmospheric scientist.

Further, the study also showed that Delhi has emerged as the most polluted city in the past ten years, with itsannual AQI readings varying between 180 and 256. Alongside Delhi, Lucknow also emerged as one of the highly polluted cities with Mumbai having average annual AQI readings between 118 to 227.

Meanwhile, experts have attributed to the cold north-westerly winds behind the continuous worse AQI in the country.

“With cold north-westerly winds sweeping into the plains, minimum temperatures are set to drop, further making it harder for pollutants to disperse. As temperatures fall, the inversion layer thickens, creating a stronger barrier that prevents sunlight and wind from breaking through and clearing the air. This season’s Western Disturbances have been weak and have failed to trigger widespread rainfall across North India. Without rain to wash pollutants out of the atmosphere, the pollution lingers for longer periods, leading to early and persistent smog-like conditions,” said Mahesh Palawat, Vice President, Meteorology and Climate Change, Skymet Weather.

Meanwhile, Mumbai on Monday recorded a reading of 128. Further, the CPCB dash board showed that out of the 21 monitoring stations in Mumbai, one showed poor AQI, while 20 of the stations showed ‘moderate’ readings.