Air Pollution To Get Worse In Mumbai This Year Due To El Nino, Experts Warn

Mumbai's worsening air quality has exposed a wider urban pollution problem, with road dust, vehicle emissions, industrial activity and construction sites all contributing. As authorities announce fresh measures, questions remain over monitoring, enforcement and the sources responsible for the city's polluted air.

But the city's air pollution crisis is likely to be aggravated by the El Niño factor, experts have told NDTV. Mumbai's coastal location does not prevent pollution from accumulating when winds are weak. Weather conditions can reduce the dispersion of emissions, while humidity and airborne sea-salt particles can contribute to visible haze.

Dr. Gufran Beig, Founder Project Director SAFAR and Chair Professor, NIAS, IISc told NDTV, "The air pollution scenario in this coming winter of 2026 is going to be very different under the influence of El Niño. This El Niño is not a normal El Niño, this is a super El Niño where the Pacific Ocean is already warm by more than 3.2 degree Celsius and it is still warming, means peak has not yet come.”

“The impact of this is that it is going to change or modulate the large-scale wind circulation. And the most important impact is likely to be in coastal areas including Mumbai, where the wind speed and directions are going to be different and providing a surprise. Specifically in a city like Mumbai, the large-scale circulations or winds are going to be slower. Slower means Mumbai will be losing its natural protection which normally the winds are relatively higher,” Dr. Beig adds.

Mumbai's coastal location has long been considered an advantage in dispersing pollution. Yet, as haze settles over the skyline and air-quality readings fluctuate sharply across neighbourhoods, the city is confronting a problem that cannot be explained by its construction boom alone.

On October 24, Mumbai's Air Quality Index (AQI) reportedly touched 322, placing it in the very poor category, while Delhi recorded 176 performing much better than Mumbai.

“When the winds are slower, it will trap the pollutants and it is likely to increase the pollutants,” Dr. Beig said indicating that Mumbai's proximity to the sea which gives it a natural protection against air pollution may not work as effectively this time as it did in the past.

Explaining how the El Niño makes the situation worse, Dr. Beig said, “The second impact of El Niño is likely to be that winter is going to be milder. When winter is relatively milder, that means it is a warmer temperature near the surface, which is rich in pollutants in winter, which is going to go up because horizontal wind speed is a little less so it will diffuse upwards. And then as we go up, obviously the temperature decreases so at which when it is reaches to 100 meters to 200 meters, it will find a cooler air.”

“When the cooler air mix with a warmer air, which are already rich in air pollutants, it will get accumulated and the haze-like layer will be formed and that is what is seen in the sky of Mumbai. So, those are the impact which El Niño is directly to be knowing and westerly disturbances are likely to be totally vanishing. That means the rain is unlikely, which is due to WD, which wash off pollutants. So, all this cumulative effect means Mumbai is going to face a pollution challenge in coming winter,” Dr. Beig added.