Is the air quality good in Kolkata, India?
As of September 5, 2026, at 7:30 PM IST (GMT+5:30), air quality in Kolkata, India, is poor, with AQI exceeding 150, classified as "unhealthy," with PM2.5 as the dominant pollutant.
Kolkata's annual average PM2.5 concentration was 51 µg/m³ in 2025, exceeding the WHO annual guideline of 5 µg/m³ by more than 10 times. Poor air quality is a persistent problem in the city, with conditions remaining unhealthy for most of the year except during the summer and monsoon months.
India's national average PM2.5 concentration in 2025 was 48.9 µg/m³, equivalent to an AQI of 134, classified as "unhealthy for sensitive groups" and 9.78 times higher than the WHO annual guideline of 5 µg/m³, placing India sixth globally.
For a complete, real-time view of current pollution levels, see Kolkata's air quality map.
Kolkata, India, ranked among the most polluted major cities globally, as of September 5, 2026, at 7:30 PM (local time). Source: IQAir.
Air quality map of Kolkata, India, as of September 5, 2026, at 7:30 PM (local time). Source: IQAir.
When will the air quality improve in Kolkata, India?
Winter months typically see a spike in PM2.5 due to a combination of lower wind speeds, temperature inversions, and increased emissions from vehicles and biomass burning, with October through February historically being Kolkata's worst months for air quality. As the monsoon retreats through September, conditions are likely to deteriorate further.
Short-term relief depends on renewed rainfall or stronger winds dispersing pollutants in the coming days.
Hourly air quality forecast for Kolkata, India, as of September 5, 2026, at 7:30 PM (local time). Source: IQAir.
What is causing poor air quality in Kolkata, India?
The causes of high pollutant concentrations in Kolkata have been identified as vehicular emissions at 51.4%, followed by industrial sources at 24.5% and dust particles at 21.1%.
Secondary pollutants are also playing an increasing role, with fine particles formed through chemical reactions between gases such as SO₂ and NH₃ now accounting for a large share of PM2.5 mass, often originating from coal power plants and other large sources (1). Three thermal power plants operating in and around Kolkata further compound the city's chronic pollution burden.
As the monsoon weakens in September, the reduced rainfall and weaker winds allow these accumulated emissions to build up near the surface rather than being washed away (2).
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
- Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
