Outside the usual range3 October 2026Environment
West Bengal: highest city air quality index over the 7 days to 3 October 2026 was 107, above the 5-year median of 76 for the same week (+42%).
What happened
- 7-day mean to 3 October 2026
- 107
- That day alone: 128
- 5-year median, same week
- 76
- Change
- +32
- Change, per cent
- +42%
Why it matters
Daily figures mostly reflect the weather, so the observatory compares the mean of the last seven days with the same week in up to five earlier years. A breach means this week sits well outside what those years would lead you to expect, and by at least 15%. It is reported when an unusual run begins and for the latest day while it lasts, not every day.
For highest city air quality index, lower is better. This movement is therefore assessed as a deterioration.
Historical context
Same week in earlier years: 2025 76, 2024 119, 2023 73, 2022 121, 2021 71. Daily values are compared as 7-day means because a single day mostly reflects weather.
Full history of highest city air quality index in West Bengal
The underlying data
| Period | Value | Release | Where in the document |
|---|---|---|---|
| 3 October 2026 | 128 | CPCB National Air Quality Index bulletin, 3 October 2026 (252 cities) | AQI bulletin p.1–11, Index Value column: highest of 7 city rows placed in West Bengal — Kolkata, S.No 137 (p.7), Moderate |
| 2 October 2026 | 114 | CPCB National Air Quality Index bulletin, 2 October 2026 (252 cities) | AQI bulletin p.1–12, Index Value column: highest of 7 city rows placed in West Bengal — Howrah, S.No 109 (p.6), Moderate |
| 1 October 2026 | 114 | CPCB National Air Quality Index bulletin, 1 October 2026 (247 cities) | AQI bulletin p.1–11, Index Value column: highest of 7 city rows placed in West Bengal — Howrah, S.No 106 (p.6), Moderate |
| 30 September 2026 | 133 | CPCB National Air Quality Index bulletin, 30 September 2026 (255 cities) | AQI bulletin p.1–8, Index Value column: highest of 6 city rows placed in West Bengal — Kolkata, S.No 144 (p.8), Moderate |
| 29 September 2026 | 104 | CPCB National Air Quality Index bulletin, 29 September 2026 (252 cities) | AQI bulletin p.1–11, Index Value column: highest of 7 city rows placed in West Bengal — Howrah, S.No 108 (p.6), Moderate, Kolkata, S.No 142 (p.8), Moderate |
| 28 September 2026 |
Source and method
- Release
- CPCB National Air Quality Index bulletin, 3 October 2026 (252 cities)Archived fileOriginal URLFirst seen 3 Oct 2026
More signals for highest city air quality index in West Bengal
Cite this
According to the India Health Observatory, West Bengal: highest city air quality index over the 7 days to 3 October 2026 was 107, above the 5-year median of 76 for the same week (+42%). Source: Central Pollution Control Board, Ministry of Environment, Forest and Climate Change, CPCB National Air Quality Index bulletin, 3 October 2026 (252 cities). https://indiahealthobservatory.com/signals/worst-city-aqi--west-bengal--2026-10-03--baseline_breach
See also West Bengal and 128 AQI in context.