Post-Diwali Pollution: Several Maharashtra Cities Record Worse Air Quality Than Mumbai

Mumbai was not the only city in Maharashtra struggling with post-Diwali pollution, with several inland urban centres recording significantly higher pollution levels.

Pimpri Chinchwad registered an AQI above 300, while Pune’s air pollution levels were nearly 2.5 times higher than the previous year. According to data recorded on November 9, as many as 13 cities in the state were in the ‘poor’ or ‘very poor’ categories.

A comparison with last year’s post-Diwali figures shows a sharp deterioration. Of the 10 most polluted cities this year, only Nanded had recorded ‘poor’ air quality on the day after Diwali in 2025. This time, all 10 featured in the same category or worse. Mumbai, meanwhile, remained in the ‘moderate’ category with an AQI of 172.

Pimpri Chinchwad tops Maharashtra’s pollution chart

According to the Central Pollution Control Board (CPCB) dashboard, the AQI recorded at 4 pm on Monday placed Pimpri Chinchwad at the top with 301. Nanded followed with 296, while Pune recorded 288. Malegaon stood at 273 and Nagpur at 268.

Other cities also reported elevated pollution levels, including Jalna (266), Parbhani (246), Jalgaon (243), Nashik (234), Akola (230), Belapur (218), Chhatrapati Sambhajinagar (211) and Chandrapur (202).

Pollution levels rise sharply compared to last year

The year-on-year comparison highlights the extent of the deterioration in several cities. Pune’s AQI increased from 115 on October 22 last year to 288 this year. Malegaon rose from 123 to 273, while Akola climbed from 109 to 230.

Pimpri Chinchwad also witnessed a significant increase, with its AQI rising from 154 to 301. Nanded, which had already recorded an AQI of 216 last year, saw a further increase of approximately 37 per cent.

Why did Mumbai fare better than inland cities?

Mumbai and several parts of the Mumbai Metropolitan Region recorded comparatively better air quality. While Mumbai’s AQI stood at 172, Bhiwandi recorded 195, Dombivli 176, Kalyan 170 and Navi Mumbai 160.

The situation varied across the region. Mira-Bhayandar saw its AQI decline from 256 to 148, whereas Bhiwandi witnessed an increase from 111 to 195.

Atmospheric scientist Gufran Beig of the National Institute of Advanced Studies (NIAS) attributed the difference partly to coastal weather conditions. He explained that an anticyclonic circulation developing over the Himalayas from November 10 brought easterly winds towards coastal areas such as Mumbai, helping disperse pollutants.

Beig said Mumbai benefited from sea breezes, while inland cities such as Pune, Pimpri Chinchwad and Nagpur lacked the same natural advantage. He also pointed to slower winds associated with El Niño conditions, which allowed pollutants from widespread firecracker use to remain trapped in the atmosphere.

Former National Environmental Engineering Research Institute (NEERI) scientist Tuhin Banerjee highlighted additional local factors. He explained that rising sea temperatures linked to El Niño had affected the usual movement of coastal winds, contributing to stagnant conditions. Firecracker emissions and industrial pollution, particularly in areas such as Chandrapur, further aggravated the situation.

Authorities announce restrictions on firecrackers

The Maharashtra Pollution Control Board (MPCB) said the widespread deterioration in air quality was largely linked to firecracker bursting. Satish Padval, joint director (Air) at the board, said instructions had been issued to municipal bodies, tehsil offices and district administrations to immediately restrict firecracker use. Police authorities were also directed to take action against people bursting crackers in public places.

In a separate move, Thane District Collector Shrikrishna Panchal prohibited rockets and similar aerial firecrackers across the district, citing public safety concerns. The Brihanmumbai Municipal Corporation (BMC) subsequently announced a similar restriction.

The restrictions will remain in force until November 25 in Mumbai and January 8, 2027, in Thane district. The orders cover the Mumbai region, excluding Vasai-Virar and Panvel.

The decisions followed a rise in fire incidents during Diwali celebrations. According to BMC figures, the Mumbai Fire Brigade received 142 fire-related calls on Sunday, of which 137 were linked to fireworks. In Thane, all 44 calls received by the fire brigade until Sunday night were attributed to firecrackers.

What do AQI levels and PM2.5 indicate?

Under the AQI classification, readings between 101 and 200 fall under the ‘moderate’ category, while 201-300 is classified as ‘poor’ and 301-400 as ‘very poor’.

Moderate air quality can affect vulnerable groups, including children and older people. Poor and very poor conditions can pose health risks across age groups, potentially causing respiratory irritation and cardiovascular complications.

The primary pollutant identified by the CPCB at the monitored locations was PM2.5. These are fine particles measuring 2.5 micrometres or less in diameter, commonly released through smoke and combustion. Their extremely small size allows them to travel deep into the respiratory system when inhaled.