Siwan vs Vellore
Side-by-side air quality comparison between Siwan 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 | Siwan | Vellore |
|---|---|---|
| PM2.5(µg/m³) | 114.60 | 7.00 |
| PM10(µg/m³) | 125.70 | 8.40 |
| NO₂(µg/m³) | 44.50 | 8.50 |
| SO₂(µg/m³) | 15.40 | 4.30 |
| O₃(µg/m³) | 54.00 | 44.00 |
| CO(µg/m³) | 761.00 | 141.00 |
CPCB Multi-Year History (2016–2024)
Summary
Overview
In 2024, Siwan averaged an AQI of 148 while Vellore averaged 61 — a 87-point (143%) gap, with Siwan the more polluted and Vellore the cleaner of the two. On 222 days when both cities reported, Vellore was cleaner on 213 of them; the average daily gap was 138 AQI points.
Seasonality & days
Siwan peaks in January, while Vellore peaks in December. Siwan logged 5.2% Severe days and 17.7% Good-or-Satisfactory days; Vellore was 0% Severe and 83.5% Good-or-Satisfactory. Longest clean-air streaks: Siwan 13 days, Vellore 23 days.
Year-over-year progress
Siwan has improved by 184 AQI points (55.4%) from 2021 to 2024; Vellore has improved by 10 AQI points (14.1%) over the same window. The worst recorded day for Siwan reached AQI 488 at Chitragupta Nagar (BSPCB) on 2022-12-30; Vellore hit AQI 245 at Vasanthapuram (TNPCB) on 2024-01-14.
Station-level disparity
Siwan spans 1 CPCB stations with a 0-point spread (min 197, max 197); 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 Siwan's 282. That's a significant difference of 270 points.