SmogRank / Countries / India / Tamil Nadu

Most polluted cities in Tamil Nadu, India

2 measured cities, last 30 days; 2 above the WHO 24-hour guideline. Worst: Chennai at 25.2 µg/m³, #110 in the world.

The 457 monitors run by CPCB in India haven't reported for more than two days. Cities that rely on them are missing from the 24-hour board and may drop from the longer ones; they return when the data does.

Estimated: cities without a monitor

Tamil Nadu cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City	7-day estimate	Band
Kallakurichi	≈ 33 µg/m³	Moderate
Madurai	≈ 14 µg/m³	Moderate
Tirunelveli	≈ 9 µg/m³	Moderate
Tiruchirappalli	≈ 25 µg/m³	Moderate
Tiruppur	≈ 21 µg/m³	Moderate
Salem	≈ 27 µg/m³	Moderate
Erode	≈ 25 µg/m³	Moderate
Vellore	≈ 44 µg/m³	Unhealthy for sensitive groups
Ambattur	≈ 43 µg/m³	Unhealthy for sensitive groups
Thoothukudi	≈ 10 µg/m³	Moderate
Avadi	≈ 43 µg/m³	Unhealthy for sensitive groups
Dindigul	≈ 24 µg/m³	Moderate
Thanjavur	≈ 21 µg/m³	Moderate
Rānipet	≈ 44 µg/m³	Unhealthy for sensitive groups
Tiruvottiyūr	≈ 39 µg/m³	Unhealthy for sensitive groups
Sivakasi	≈ 11 µg/m³	Moderate
Karur	≈ 22 µg/m³	Moderate
Pallāvaram	≈ 38 µg/m³	Unhealthy for sensitive groups
Ooty	≈ 12 µg/m³	Moderate
Hosūr	≈ 29 µg/m³	Moderate
Nāgercoil	≈ 8 µg/m³	Good
Kanchipuram	≈ 43 µg/m³	Unhealthy for sensitive groups
Kumarapalayam	≈ 28 µg/m³	Moderate
Kāraikkudi	≈ 12 µg/m³	Moderate
Neyveli	≈ 35 µg/m³	Moderate
Tambaram	≈ 38 µg/m³	Unhealthy for sensitive groups
Kumbakonam	≈ 24 µg/m³	Moderate
Tiruvannamalai	≈ 44 µg/m³	Unhealthy for sensitive groups
Rajapalayam	≈ 11 µg/m³	Moderate
Kurichchi	≈ 17 µg/m³	Moderate
Madhavaram	≈ 39 µg/m³	Unhealthy for sensitive groups
Pudukkottai	≈ 14 µg/m³	Moderate
Ambur	≈ 34 µg/m³	Moderate
Nagapattinam	≈ 26 µg/m³	Moderate
Villupuram	≈ 37 µg/m³	Unhealthy for sensitive groups
Kuniyamuttūr	≈ 17 µg/m³	Moderate
Paramagudi	≈ 13 µg/m³	Moderate
Tiruchengode	≈ 28 µg/m³	Moderate
Vaniyambadi	≈ 34 µg/m³	Moderate
Kovilpatti	≈ 11 µg/m³	Moderate

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SmogRank, most polluted cities in Tamil Nadu, India, PM2.5, last 30 days to 2 Oct 2026, 00:00 UTC, smogrank.com/in/region/tamil-nadu?w=30d.

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Updated 2026-10-02 00:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.