Outside the usual range21 September 2026Environment
India: average air quality index over the 7 days to 21 September 2026 was 71, above the 5-year median of 61 for the same week (+18%).
What happened
- 7-day mean to 21 September 2026
- 71
- That day alone: 80
- 5-year median, same week
- 61
- Change
- +11
- Change, per cent
- +18%
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 average air quality index, lower is better. This movement is therefore assessed as a deterioration.
Historical context
Same week in earlier years: 2025 61, 2024 70, 2023 60, 2022 67, 2021 60. Daily values are compared as 7-day means because a single day mostly reflects weather.
The underlying data
| Period | Value | Release | Where in the document |
|---|---|---|---|
| 21 September 2026 | 80 | CPCB National Air Quality Index bulletin, 21 September 2026 (242 cities) | AQI bulletin p.1–13, Index Value column: mean of all 242 city rows — every row in the table |
| 20 September 2026 | 79 | CPCB National Air Quality Index bulletin, 20 September 2026 (243 cities) | AQI bulletin p.1–13, Index Value column: mean of all 243 city rows — every row in the table |
| 19 September 2026 | 69 | CPCB National Air Quality Index bulletin, 19 September 2026 (243 cities) | AQI bulletin p.1–13, Index Value column: mean of all 243 city rows — every row in the table |
| 18 September 2026 | 64 | CPCB National Air Quality Index bulletin, 18 September 2026 (249 cities) | AQI bulletin p.1–13, Index Value column: mean of all 249 city rows — every row in the table |
| 17 September 2026 | 72 | CPCB National Air Quality Index bulletin, 17 September 2026 (245 cities) | AQI bulletin p.1–13, Index Value column: mean of all 245 city rows — every row in the table |
| 16 September 2026 | 69 |
Source and method
- Release
- CPCB National Air Quality Index bulletin, 21 September 2026 (242 cities)Archived fileOriginal URLFirst seen 3 Oct 2026
More signals for average air quality index in India
- India: average air quality index over the 7 days to 2 October 2026 was 80, above the 5-year median of 63 for the same week (+27%).
- India: average air quality index of 103 on 2 October 2026 is the highest since 26 May 2026.
- India: average air quality index over the 7 days to 26 September 2026 was 77, above the 5-year median of 66 for the same week (+17%).
- India: average air quality index over the 7 days to 10 September 2026 was 68, above the 5-year median of 58 for the same week (+18%).
Cite this
According to the India Health Observatory, India: average air quality index over the 7 days to 21 September 2026 was 71, above the 5-year median of 61 for the same week (+18%). Source: Central Pollution Control Board, Ministry of Environment, Forest and Climate Change, CPCB National Air Quality Index bulletin, 21 September 2026 (242 cities). https://indiahealthobservatory.com/signals/air-quality-index--india--2026-09-21--baseline_breach
See also India and 80 AQI in context.