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Coimbatore vs Purnia

Side-by-side air quality comparison between Coimbatore and Purnia.

Cleaner right now: Coimbatore (269-pt gap)Historical head-to-head: Coimbatore cleaner 436/469 daysYoY 20192024: Coimbatore -7% · Purnia -55.1%

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

🏆 Cleaner

Coimbatore

Tamil Nadu, India

Good

PM2.5: 2.7 µg/m³

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VS

Purnia

Bihar, India

Poor

PM2.5: 112.0 µg/m³

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Pollutant-level comparison (PM2.5, PM10, O3, NO2, SO2, CO)
PollutantCoimbatorePurnia
PM2.5(µg/m³)2.70112.00
PM10(µg/m³)2.90115.70
NO₂(µg/m³)4.5031.10
SO₂(µg/m³)2.2018.40
O₃(µg/m³)43.0042.00
CO(µg/m³)159.00756.00

CPCB Multi-Year History (2016–2024)

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Summary

Overview

In 2024, Coimbatore averaged an AQI of 66 while Purnia averaged 133 — a 67-point (102%) gap, with Purnia the more polluted and Coimbatore the cleaner of the two. On 469 days when both cities reported, Coimbatore was cleaner on 436 of them; the average daily gap was 105 AQI points.

Seasonality & days

Coimbatore peaks in November, while Purnia peaks in January. Coimbatore logged 0% Severe days and 90.5% Good-or-Satisfactory days; Purnia was 3.7% Severe and 33.699999999999996% Good-or-Satisfactory. Longest clean-air streaks: Coimbatore 32 days, Purnia 14 days.

Year-over-year progress

Coimbatore has improved by 5 AQI points (7%) from 2019 to 2024; Purnia has improved by 163 AQI points (55.1%) over the same window. The worst recorded day for Coimbatore reached AQI 279 at SIDCO Kurichi (TNPCB) on 2024-09-28; Purnia hit AQI 460 at Mariam Nagar (BSPCB) on 2022-12-15.

Station-level disparity

Coimbatore spans 2 CPCB stations with a 1-point spread (min 63, max 64); Purnia spans 1 stations with a 0-point spread (min 176, max 176).

Verdict

🏆 Coimbatore has better air quality with an AQI of 5 compared to Purnia's 274. That's a significant difference of 269 points.

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