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Patna vs Salem

Side-by-side air quality comparison between Patna and Salem.

Cleaner right now: Salem (205-pt gap)Historical head-to-head: Salem cleaner 388/394 daysYoY 20162024: Patna -18.9% · Salem -6.8%

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

Patna

Bihar, India

Poor

PM2.5: 97.8 µg/m³

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VS
🏆 Cleaner

Salem

Tamil Nadu, India

Good

PM2.5: 12.9 µg/m³

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Pollutant-level comparison (PM2.5, PM10, O3, NO2, SO2, CO)
PollutantPatnaSalem
PM2.5(µg/m³)97.8012.90
PM10(µg/m³)109.4015.80
NO₂(µg/m³)40.5017.10
SO₂(µg/m³)18.907.50
O₃(µg/m³)52.0030.00
CO(µg/m³)667.00243.00

CPCB Multi-Year History (2016–2024)

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Summary

Overview

In 2024, Patna averaged an AQI of 172 while Salem averaged 68 — a 104-point (153%) gap, with Patna the more polluted and Salem the cleaner of the two. On 394 days when both cities reported, Salem was cleaner on 388 of them; the average daily gap was 196 AQI points.

Seasonality & days

Patna peaks in December, while Salem peaks in April. Patna logged 7.5% Severe days and 19.400000000000002% Good-or-Satisfactory days; Salem was 0% Severe and 87.1% Good-or-Satisfactory. Longest clean-air streaks: Patna 30 days, Salem 17 days.

Year-over-year progress

Patna has improved by 40 AQI points (18.9%) from 2016 to 2024; Salem has improved by 5 AQI points (6.8%) over the same window. The worst recorded day for Patna reached AQI 491 at IGSC Planetarium Complex (BSPCB) on 2016-01-01; Salem hit AQI 214 at Sona College of Technology (TNPCB) on 2024-01-15.

Station-level disparity

Patna spans 6 CPCB stations with a 39-point spread (min 154, max 193); Salem spans 1 stations with a 0-point spread (min 73, max 73).

Verdict

🏆 Salem has better air quality with an AQI of 22 compared to Patna's 227. That's a significant difference of 205 points.

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