Coimbatore vs Siwan
Side-by-side air quality comparison between Coimbatore and Siwan.
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 | Coimbatore | Siwan |
|---|---|---|
| PM2.5(µg/m³) | 2.70 | 114.60 |
| PM10(µg/m³) | 2.90 | 125.70 |
| NO₂(µg/m³) | 4.50 | 44.50 |
| SO₂(µg/m³) | 2.20 | 15.40 |
| O₃(µg/m³) | 43.00 | 54.00 |
| CO(µg/m³) | 159.00 | 761.00 |
CPCB Multi-Year History (2016–2024)
Summary
Overview
In 2024, Coimbatore averaged an AQI of 66 while Siwan averaged 148 — a 82-point (124%) gap, with Siwan the more polluted and Coimbatore the cleaner of the two. On 394 days when both cities reported, Coimbatore was cleaner on 366 of them; the average daily gap was 123 AQI points.
Seasonality & days
Coimbatore peaks in November, while Siwan peaks in January. Coimbatore logged 0% Severe days and 90.5% Good-or-Satisfactory days; Siwan was 5.2% Severe and 17.7% Good-or-Satisfactory. Longest clean-air streaks: Coimbatore 32 days, Siwan 13 days.
Year-over-year progress
Coimbatore has improved by 5 AQI points (7%) from 2019 to 2024; Siwan has improved by 184 AQI points (55.4%) over the same window. The worst recorded day for Coimbatore reached AQI 279 at SIDCO Kurichi (TNPCB) on 2024-09-28; Siwan hit AQI 488 at Chitragupta Nagar (BSPCB) on 2022-12-30.
Station-level disparity
Coimbatore spans 2 CPCB stations with a 1-point spread (min 63, max 64); Siwan spans 1 stations with a 0-point spread (min 197, max 197).
Verdict
🏆 Coimbatore has better air quality with an AQI of 5 compared to Siwan's 282. That's a significant difference of 277 points.