Chennai vs Kolkata
Side-by-side air quality comparison between Chennai and Kolkata.
Live AQI from Open-Meteo CAMS (~45 km global model, updated hourly). Multi-year history from CPCB station data via aqinow.co pipeline (2016–2024, station-level daily records).
AQI Comparison
Pollutant-level comparison (PM2.5, PM10, O3, NO2, SO2, CO)▾
| Pollutant | Chennai | Kolkata |
|---|---|---|
| PM2.5(µg/m³) | 13.90 | 68.70 |
| PM10(µg/m³) | 15.30 | 72.60 |
| NO₂(µg/m³) | 15.00 | 22.20 |
| SO₂(µg/m³) | 9.10 | 11.50 |
| O₃(µg/m³) | 56.00 | 55.00 |
| CO(µg/m³) | 316.00 | 364.00 |
CPCB Multi-Year History (2016–2024)
Summary
Overview
In 2024, Chennai averaged an AQI of 68 while Kolkata averaged 101 — a 33-point (49%) gap, with Kolkata the more polluted and Chennai the cleaner of the two. On 2072 days when both cities reported, Chennai was cleaner on 1168 of them; the average daily gap was 84 AQI points.
Seasonality & days
Chennai peaks in December, while Kolkata peaks in January. Chennai logged 0% Severe days and 57.5% Good-or-Satisfactory days; Kolkata was 1% Severe and 47.800000000000004% Good-or-Satisfactory. Longest clean-air streaks: Chennai 53 days, Kolkata 75 days.
Year-over-year progress
Chennai has improved by 25 AQI points (26.9%) from 2017 to 2024; Kolkata has improved by 76 AQI points (42.9%) over the same window. The worst recorded day for Chennai reached AQI 391 at Kodungaiyur (TNPCB) on 2021-05-14; Kolkata hit AQI 453 at Rabindra Bharati University (WBPCB) on 2019-01-23.
Station-level disparity
Chennai spans 9 CPCB stations with a 27-point spread (min 63, max 90); Kolkata spans 7 stations with a 56-point spread (min 95, max 151).
Verdict
🏆 Chennai has better air quality with an AQI of 23 compared to Kolkata's 130. That's a significant difference of 107 points.