Chennai vs Vellore
Side-by-side air quality comparison between Chennai and Vellore.
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 | Vellore |
|---|---|---|
| PM2.5(µg/m³) | 11.70 | 7.00 |
| PM10(µg/m³) | 13.10 | 8.40 |
| NO₂(µg/m³) | 14.20 | 8.50 |
| SO₂(µg/m³) | 10.10 | 4.30 |
| O₃(µg/m³) | 56.00 | 44.00 |
| CO(µg/m³) | 308.00 | 141.00 |
CPCB Multi-Year History (2016–2024)
Summary
Overview
In 2024, Chennai averaged an AQI of 68 while Vellore averaged 61 — a 7-point (11%) gap, with Chennai the more polluted and Vellore the cleaner of the two. On 234 days when both cities reported, Vellore was cleaner on 211 of them; the average daily gap was 43 AQI points.
Seasonality & days
Both cities see their worst air in December on average. Chennai logged 0% Severe days and 57.5% Good-or-Satisfactory days; Vellore was 0% Severe and 83.5% Good-or-Satisfactory. Longest clean-air streaks: Chennai 53 days, Vellore 23 days.
Year-over-year progress
Chennai has improved by 25 AQI points (26.9%) from 2017 to 2024; Vellore has improved by 10 AQI points (14.1%) over the same window. The worst recorded day for Chennai reached AQI 391 at Kodungaiyur (TNPCB) on 2021-05-14; Vellore hit AQI 245 at Vasanthapuram (TNPCB) on 2024-01-14.
Station-level disparity
Chennai spans 9 CPCB stations with a 27-point spread (min 63, max 90); Vellore spans 1 stations with a 0-point spread (min 70, max 70).
Verdict
🏆 Vellore has better air quality with an AQI of 12 compared to Chennai's 20.