Kolkata Air Quality Index (AQI) & Air Pollution Today

West Bengal, India — Real-time Air Quality Index (AQI) and PM2.5

Kolkata AQI Right Now

65

Category: Satisfactory

Dominant Pollutant: pm10

PM2.5: 31.81 µg/m³

PM10: 64.07 µg/m³

Last updated: 2026-03-24 — Data source: Google Air Quality API (NAQI). Live NAQI values load when you visit the page.

Kolkata Pollutant Levels

PollutantConcentration
PM2.531.81 µg/m³
PM1064.07 µg/m³
O₃ (Ozone)18.81 µg/m³
NO₂20.42 µg/m³
SO₂2.47 µg/m³
CO302 µg/m³

Health Advisory — Kolkata

Satisfactory: Minor breathing discomfort to sensitive people.

Health Impact — Kolkata

Cigarette Equivalent: Breathing this air is equivalent to smoking 1.4 cigarettes per day (based on current PM2.5 levels).

Life Expectancy Impact: Sustained exposure at this PM2.5 level could reduce life expectancy by 0.14 years (AQLI estimate, relative to WHO guideline of 5 µg/m³).

Health Recommendations for Kolkata

  • General Population: Acceptable air quality. Unusually sensitive people should limit prolonged outdoor exertion.
  • Elderly: Minor breathing discomfort is possible.
  • Children: Should be fine outdoors with normal activities.
  • Lung Disease Patients: Consider reducing prolonged outdoor exertion.

Understanding Kolkata Air Quality

Kolkata, India's third-largest metropolitan area, sits in the low-lying Ganges delta where the Hooghly River creates a humid subtropical environment. The city's dense urban fabric - one of the highest population densities in the world - concentrates vehicular and domestic emissions in narrow corridors, while the surrounding industrial belts of Howrah and Hooghly contribute factory emissions.

Winter months (November–February) bring the worst air quality as the northeast monsoon's dry phase reduces atmospheric cleansing. PM2.5 during this period regularly exceeds 150 µg/m³, with post-Diwali and post-Kali Puja spikes pushing readings above 300 µg/m³ in November. The combination of brick kiln emissions from the city's periurban ring and agricultural residue burning in Bihar adds to the winter pollution load. Dense morning fog during December–January reduces visibility and compresses the atmospheric mixing layer.

The southwest monsoon (June–September) delivers dramatic improvement, with heavy rainfall washing out particulates and AQI dropping to Good levels. However, post-monsoon (October) sees waste burning and construction activity resume. Kolkata's oldest challenge - vehicular pollution from its bus fleet and two-stroke autorickshaws - has improved with the introduction of CNG buses and electric vehicles, but the sheer density of traffic on roads like EM Bypass and AJC Bose Road keeps NOx levels elevated.

Primary Pollution Sources

  • Vehicle exhaust
  • Industrial emissions (Howrah, Hooghly belt)
  • Construction dust
  • Waste burning
  • Brick kilns (periurban)
  • Port and shipping emissions

Geography: Ganges delta at sea level; subtropical humid climate with dense urban fabric, river proximity, and seasonal monsoon flushing

Peak pollution months: November, December, January, February

Frequently Asked Questions — Kolkata

What is the most polluted month in Kolkata?

November is typically the worst month due to the dual impact of Diwali/Kali Puja firecracker emissions and the onset of dry, cool weather that suppresses atmospheric mixing. PM2.5 can exceed 300 µg/m³ during festive spikes, with December and January remaining in the Poor to Very Poor range.

What causes air pollution in Kolkata?

Kolkata's pollution comes from vehicular exhaust (dense traffic in a compact city), industrial emissions from the Howrah-Hooghly manufacturing belt, periurban brick kilns (over 300 in the metropolitan area), construction dust, waste burning, and port/shipping emissions. Seasonal factors include agricultural burning in neighboring Bihar and festival fireworks.

Air Quality in Nearby Cities