Uttarakhand: average air quality index over the 7 days to 28 September 2026 was 49, below the 3-year median of 71 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.

The number being averaged changed (about 2 now against 3 in earlier years), so part of this reflects which places are measured. Same week in earlier years: 2025 71, 2024 50, 2023 72. Daily values are compared as 7-day means because a single day mostly reflects weather.

Full history of average air quality index in Uttarakhand