Delhi records lowest September AQI in five years at 102, highest ‘moderate’ air quality days in 2026

Delhi recorded its lowest monthly average Air Quality Index (AQI) for September in the last five years, with the overall improvement in air quality continuing in 2026, the Ministry of Environment, Forest and Climate Change said on Wednesday.

According to the ministry, Delhi recorded a monthly average AQI of 102 in September 2026, which was lower than the monthly average recorded during the corresponding period in each of the previous five years.

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September AQI lowest in five years

The monthly average AQI was recorded at 105 in September 2025, 105 in 2024, 108 in 2023 and 104 in 2022.

The ministry also said that the January-September period of 2026 witnessed the highest number of days with a daily average AQI below 200, which falls under the ‘Moderate’ category, in the last five years.

Delhi recorded 194 days with a daily average AQI below 200 during the January-September period in 2026. This was higher than the 187 such days recorded during the same period in 2025, 188 days in 2024, 193 days in 2023 and 146 days in 2022.

‘Poor to Severe’ days at five-year low

At the same time, the January-September period of 2026 recorded the lowest number of days with ‘Poor to Severe’ air quality in the last five years.

Delhi recorded 79 ‘Poor to Severe’ air quality days during this period in 2026. In comparison, the city recorded 86 such days in both 2025 and 2024, 80 days in 2023 and 127 days in 2022.

The ministry further stated that the average PM2.5 concentration recorded in Delhi from January 1 to September 28, 2026, was among the lowest recorded since 2022.

Delhi recorded an average PM2.5 concentration of 69 micrograms per cubic metre (µg/m³) in 2026, the same as the average recorded in 2025.

The average PM2.5 concentration was recorded at 81 µg/m³ in 2024, 73 µg/m³ in 2023 and 80 µg/m³ in 2022.

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CAQM to intensify anti-pollution measures

The Commission for Air Quality Management (CAQM) is working closely with various stakeholders to take effective measures for the prevention, control and abatement of air pollution and improve air quality in Delhi-NCR, the ministry said.

"These efforts will be further intensified with an endeavour to improve the air quality scenario in Delhi-NCR in the coming days," the ministry added.

The statement comes ahead of the winter season, when Delhi-NCR generally witnesses a deterioration in air quality due to multiple factors, including meteorological conditions and emission sources.