Delhi Records Lowest October Average AQI in Eight Years at 166

Delhi recorded an average Air Quality Index of 166 in October 2026, the lowest October reading in eight years. The Union Environment Ministry released the figure on 31 October, comparing it with 223 in 2025, 234 in 2024, 219 in 2023, 210 in 2022, 173 in 2021, 265 in 2020, 234 in 2019 and 269 in 2018.

For the January-to-October period the capital's average AQI was 167, better than 170 in 2025 and 184 in 2024. The city logged 220 days in the good-to-moderate category (daily average below 200) during the first ten months, the highest count since 2018 excluding the pandemic year of 2020. Days in the poor-to-severe category fell to 84, down from 104 in both 2025 and 2024.

Average PM2.5 concentration from 1 January to 29 October stood at 69 micrograms per cubic metre, below the 72 recorded in 2025 and 83 in 2024. PM10 averaged 171 micrograms per cubic metre. One day in late October saw the AQI drop to 60 after heavy rain, the cleanest October reading since 10 October 2022.

Meteorology played a central role. Delhi received well above-normal rainfall in October, including a 24-hour total of 61.4 mm that made one day the wettest in four years. The late timing of Diwali shifted firecracker emissions out of the October window, and farm-stubble burning contributed less than in recent years. Analysts at the Centre for Science and Environment noted that the improvement is largely weather-driven and does not yet indicate a structural change in emissions.

The Commission for Air Quality Management has already issued graded-response measures for the coming winter, including reduced office attendance and construction pauses in parts of the NCR from early November. Residents still face the usual seasonal rise once winter inversion sets in. The October figure provides a temporary baseline; sustained gains will depend on source-control measures once meteorological conditions turn unfavourable.