SmogRank / India / Tamil Nadu / Coimbatore
Coimbatore, month by month
Coimbatore has a measured daily mean on 434 days since 19 February 2025. Its worst month was November 2025, at 136 US AQI (49.6 µg/m³), 175th of 2,715 cities on that month's world ranking. Its cleanest was August 2025, at 62 US AQI (14.8 µg/m³).
Every month since 2025
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
Months without a mean, and why
8 months
| Month | Why |
|---|---|
| Oct 2026 | 3 of 12 days measured; a month needs 9. The others: 5 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours). |
| Sep 2026 | 1 of 30 days measured; a month needs 21. The others: 1 with readings for part of the day (a day needs 18 hours), 28 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | 2 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Jul 2026 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| May 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 10 of 28 days measured; a month needs 20. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Coimbatore's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| November 2025 | 13649.6 µg/m³ | 175thof 2,715 | Southern India, November 2025 |
| December 2025 | 12846.5 µg/m³ | 224thof 3,006 | – |
| October 2025 | 11440.8 µg/m³ | 135thof 2,614 | Southern India, 12 to 14 October 2025 |
| March 2025 | 10938.7 µg/m³ | 174thof 2,862 | – |
| February 2026 | 9633.4 µg/m³ | 214thof 2,866 | – |
| March 2026 | 9331.7 µg/m³ | 228thof 2,971 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Coimbatore's worst days
| Day | US AQI | Episode |
|---|---|---|
| 20 Oct 2025 | 209134.0 µg/m³ | – |
| 21 Oct 2025 | 18198.8 µg/m³ | – |
| 14 Oct 2025 | 16677.6 µg/m³ | Southern India, 12 to 14 October 2025 |
| 14 Nov 2025 | 16676.8 µg/m³ | Southern India, November 2025 |
| 6 Dec 2025 | 16474.7 µg/m³ | – |
| 11 Nov 2025 | 16271.6 µg/m³ | Southern India, November 2025 |
| 29 Nov 2025 | 16271.2 µg/m³ | – |
| 12 Nov 2025 | 16271.1 µg/m³ | Southern India, November 2025 |
| 29 Apr 2026 | 16271.1 µg/m³ | – |
| 31 Dec 2025 | 16169.6 µg/m³ | – |
Daily means, the highest since 19 Feb 2025; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Coimbatore, India, 19 Feb 2025 – 7 Oct 2026. Monitor data from CPCB via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/in/coimbatore/history (accessed 12 Oct 2026).
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.
Coimbatore now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).