Delhi: average air quality index over the 7 days to 29 September 2026 was 90, below the 5-year median of 131 for the same week (−31%).

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 an improvement.

This is a small-sample figure (e.g. a single monitoring city). Same week in earlier years: 2025 131, 2024 131, 2023 134, 2022 95, 2021 85. Daily values are compared as 7-day means because a single day mostly reflects weather.

Full history of average air quality index in Delhi