Coimbatore — AQI Trends
Year-over-year AQI trajectory for Coimbatore (2019–2024). Based on CPCB station data, 2016–present.
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Coimbatore — annual AQI 2019–2024
Year × month heatmap
Worst single days on record
- 2024-09-28SIDCO Kurichi (TNPCB)279
- 2022-11-23SIDCO Kurichi (TNPCB)204
- 2024-12-15PSG College of Arts and Science (TNPCB)187
- 2024-12-17PSG College of Arts and Science (TNPCB)186
- 2024-09-25SIDCO Kurichi (TNPCB)185
- 2024-01-15PSG College of Arts and Science (TNPCB)185
- 2022-12-23SIDCO Kurichi (TNPCB)180
- 2024-01-14PSG College of Arts and Science (TNPCB)177
- 2024-09-24SIDCO Kurichi (TNPCB)175
- 2021-11-03SIDCO Kurichi (TNPCB)168
What the numbers say
Overview
Coimbatore's AQI moved from 71 in 2019 to 66 in 2024 — a fall of 7.0% over 5 years. The long-run trend is roughly stable, with a regression slope of -0.6 AQI points per year.
The data story
The worst recorded year in Coimbatore was 2021 at AQI 83, while the best was 2020 at AQI 56. The city has posted 0.2% of all measured days above AQI 200 (the Poor threshold), and its worst recorded single day hit 279 on 28 Sep 2024.
Why this pattern
Coimbatore's trend has been stable — neither clearly worsening nor clearly improving. That stability often masks underlying growth in emissions being offset by cleaner vehicle technology or weather variability. The NCAP era from 2019 onward is the key policy backdrop; stability here means targets have not yet translated into measurable ground-level change.
What to do with this
For planners and residents, the trend matters as much as today's number. A worsening city needs aggressive source control and personal protection investments like indoor purifiers. An improving city rewards continued policy pressure but still requires caution during peak months. Use the live AQI page for day-to-day decisions and this chart for multi-year context. Year-over-year change of more than 10% in either direction is typically real signal, not noise.