Chennai vs Purnia
Side-by-side air quality comparison between Chennai and Purnia.
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 | Purnia |
|---|---|---|
| PM2.5(µg/m³) | 11.70 | 105.90 |
| PM10(µg/m³) | 13.10 | 109.00 |
| NO₂(µg/m³) | 14.20 | 25.20 |
| SO₂(µg/m³) | 10.10 | 20.10 |
| O₃(µg/m³) | 56.00 | 67.00 |
| CO(µg/m³) | 308.00 | 707.00 |
CPCB Multi-Year History (2016–2024)
Summary
Overview
In 2024, Chennai averaged an AQI of 68 while Purnia averaged 133 — a 65-point (96%) gap, with Purnia the more polluted and Chennai the cleaner of the two. On 603 days when both cities reported, Chennai was cleaner on 417 of them; the average daily gap was 90 AQI points.
Seasonality & days
Chennai peaks in December, while Purnia peaks in January. Chennai logged 0% Severe days and 57.5% Good-or-Satisfactory days; Purnia was 3.7% Severe and 33.699999999999996% Good-or-Satisfactory. Longest clean-air streaks: Chennai 53 days, Purnia 14 days.
Year-over-year progress
Chennai has improved by 25 AQI points (26.9%) from 2017 to 2024; Purnia has improved by 163 AQI points (55.1%) over the same window. The worst recorded day for Chennai reached AQI 391 at Kodungaiyur (TNPCB) on 2021-05-14; Purnia hit AQI 460 at Mariam Nagar (BSPCB) on 2022-12-15.
Station-level disparity
Chennai spans 9 CPCB stations with a 27-point spread (min 63, max 90); Purnia spans 1 stations with a 0-point spread (min 176, max 176).
Verdict
🏆 Chennai has better air quality with an AQI of 20 compared to Purnia's 253. That's a significant difference of 233 points.