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Out of 33 major cities in the state, Mumbai ranks 26th, placing it in the lower half. Within the Mumbai Metropolitan Region (MMR), its position is mixed, performing better than Navi Mumbai (22) and Virar (24), but worse than Mira Bhayandar (29) and Thane (33), which is the least polluted city in the state.

On a larger scale, Mumbai ranks 358th out of around 9500 cities globally and 150th in India, according to the IQAir World Air Quality Report 2025, which analysed data from 9446 cities across 143 countries.

Thick layer of haze and smog around Coastal Road in Mumbai earlier this year. File pic/ASHISH RAJE

The report also highlights a broader crisis. India is the sixth-most polluted country in the world, behind Pakistan, Bangladesh, Tajikistan, Chad and Congo. The world’s most polluted city is Loni in Ghaziabad, with PM2.5 levels of 112.5 µg/m³, over 22 times the WHO guideline.

Globally, the burden is concentrated in the region, with the 25 most polluted cities located across India, Pakistan and China, and India accounting for three of the four worst. 

What’s driving the pollution (CPCB)

Winter (Jan-Feb): Dust-driven pollution
>> Dominant pollutant: PM10
>> Sources: construction, road dust, and infrastructure activity
>> Weather: cooler temperatures and low wind trap pollutants

March onwards: Shift to emissions

>> Dominant pollutant: NO
>> Source: vehicle emissions and fuel combustion
>> Rising temperatures reduce dust but increase the emission impact 

Seasonal pattern (IQAir)

Mumbai’s pollution follows a clear cycle:
>> November to February: worst air quality, often exceeding WHO limits by over 10 times
>> August (monsoon): cleanest period, but still 2 to 3 times above safe limits

Monthly snapshot

January  8 satisfactory, 23 moderate
February 7 satisfactory, 21 moderate
March  19 satisfactory, 5 moderate 

Delhi comparison (IQAir)

Mumbai is often benchmarked against Delhi. Delhi is ranked 4th most polluted city, while New Delhi is 16th most polluted city in the world.  

2026 so far (Jan 1 – Mar 24) (CPCB)

Total days analysed: 83 
Worst AQI: 145 (February 21)
Moderate: 49 days (59 percent)
Satisfactory: 34 days (41 percent)

2025 snapshot (CPCB)

Good days 55
Satisfactory 167
Moderate 142
Unhealthy 1
60 per cent of the year fell under good or satisfactory AQI

Where Mumbai stands

State rank: 26 / 33
Global rank: 358 / 9446

Within MMR

Navi Mumbai more polluted (295 globally)
Mumbai 358 globally
Thane less polluted (437 globally)
Kalyan: 265 (global ranking)
Mira Bhayandar: 382
Virar: 332
Pune: 267
Lonavala: 249

Where money goes  (IQAir)

13 percent
Vehicle emissions 

15 percent
Biomass burning

1 percent
Industrial pollution 

63 percent
Road dust control