SmogRank / World / Asia / India / Tamil Nadu

Most polluted cities in Tamil Nadu, India

4 measured cities, this year; 4 above the WHO annual guideline. Worst: Gummidipundi at 66.5 µg/m³, #16 in the world.

464 monitors 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; that isn't clean air, and they return when the data does.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.

← Gummidipundi 97% 90%0

Every measured city in Tamil Nadu, India, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.

1Gummidipundilast full day 30 Sept 97%
2Neelankarailast full day 27 Sept 25%
3Chennai 19%
4Naduvattamlast full day 30 Sept 0%

Good0–50

Moderate51–100

Sensitive groups101–150

Unhealthy151–200

Very unhealthy201–300

Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

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	≈ 30 µg/m³	Moderate
Madurai	≈ 18 µg/m³	Moderate
Tirunelveli	≈ 15 µg/m³	Moderate
Tiruchirappalli	≈ 21 µg/m³	Moderate
Tiruppur	≈ 23 µg/m³	Moderate
Salem	≈ 25 µg/m³	Moderate
Erode	≈ 22 µg/m³	Moderate
Vellore	≈ 33 µg/m³	Moderate
Ambattur	≈ 32 µg/m³	Moderate
Thoothukudi	≈ 15 µg/m³	Moderate
Avadi	≈ 32 µg/m³	Moderate
Dindigul	≈ 18 µg/m³	Moderate
Thanjavur	≈ 22 µg/m³	Moderate
Rānipet	≈ 33 µg/m³	Moderate
Tiruvottiyūr	≈ 25 µg/m³	Moderate
Sivakasi	≈ 16 µg/m³	Moderate
Karur	≈ 18 µg/m³	Moderate
Pallāvaram	≈ 27 µg/m³	Moderate
Ooty	≈ 14 µg/m³	Moderate
Hosūr	≈ 25 µg/m³	Moderate
Nāgercoil	≈ 15 µg/m³	Moderate
Kanchipuram	≈ 30 µg/m³	Moderate
Kumarapalayam	≈ 24 µg/m³	Moderate
Kāraikkudi	≈ 15 µg/m³	Moderate
Neyveli	≈ 25 µg/m³	Moderate
Tambaram	≈ 27 µg/m³	Moderate
Kumbakonam	≈ 22 µg/m³	Moderate
Tiruvannamalai	≈ 32 µg/m³	Moderate
Rajapalayam	≈ 16 µg/m³	Moderate
Kurichchi	≈ 20 µg/m³	Moderate
Madhavaram	≈ 25 µg/m³	Moderate
Pudukkottai	≈ 18 µg/m³	Moderate
Ambur	≈ 30 µg/m³	Moderate
Nagapattinam	≈ 15 µg/m³	Moderate
Villupuram	≈ 26 µg/m³	Moderate
Kuniyamuttūr	≈ 20 µg/m³	Moderate
Paramagudi	≈ 17 µg/m³	Moderate
Tiruchengode	≈ 23 µg/m³	Moderate
Vaniyambadi	≈ 30 µg/m³	Moderate
Kovilpatti	≈ 16 µg/m³	Moderate

Bad-air episodes in Tamil Nadu

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

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SmogRank, most polluted cities in Tamil Nadu, India, PM2.5, this year to 6 Oct 2026, 23:00 UTC, smogrank.com/in/region/tamil-nadu?w=year.

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.