Delhi recorded its most polluted start to October in four years on Thursday, with the city’s average Air Quality Index (AQI) rising to 166 and falling in the ‘moderate’ category, according to data.
The last time Delhi recorded a higher AQI on October 1 was in 2022, when the index stood at 186, also in the ‘moderate’ category, according to an analysis by the Centre for Research on Energy and Clean Air (CREA).
Of the 44 monitoring stations across the national capital, 37 recorded ‘moderate’ air quality, while five stations reported ‘poor’ air quality and two recorded ‘satisfactory’ air quality, according to Central Pollution Control Board (CPCB) data.
Among the stations recording ‘poor’ air quality were Dwarka Sector 8 at 214, IIT Delhi at 248, Jahangirpuri
at 218 and Narela at 205.
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Delhi’s air quality had remained relatively better following rainfall over the weekend. The city’s AQI was around 100 in the aftermath of the rain before rising to 129 on Wednesday.
The deterioration comes immediately after a relatively cleaner September. Delhi recorded a monthly average AQI of 102 in September 2026, the lowest September average in the past five years, according to the Ministry of Environment, Forest and Climate Change. The figure was 105 in both 2025 and 2024, 108 in 2023 and 104 in 2022.
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Delhi AQI Forecast
The Air Quality Early Warning System has forecast that Delhi’s air quality will remain in the ‘moderate’ category from October 2 to 4. It is then likely to remain between the ‘moderate’ and ‘satisfactory’ categories over the following six days.
The system has warned that a ventilation index below 6,000 square metres per second, coupled with average wind speeds below 10 kmph, is unfavourable for the dispersion of pollutants. Such conditions can lead to the accumulation of pollutants close to the surface.
Under the CPCB’s classification, an AQI of 0-50 is considered ‘good’, 51-100 ‘satisfactory’, 101-200 ‘moderate’, 201-300 ‘poor’, 301-400 ‘very poor’ and 401-500 ‘severe’.
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Farm Fires
Meanwhile, the Indian Agricultural Research Institute recorded four stubble-burning incidents in Punjab, five in Uttar Pradesh and 14 in Madhya Pradesh on Thursday.
A total of 137 farm-fire incidents have been recorded between September 15 and October 1, according to the data. One farm-fire incident was reported in Delhi on September 19.
Delhi Weather
The maximum temperature at Safdarjung, Delhi’s primary weather station, settled at 35.2 degrees Celsius on Thursday, 0.5 degrees above normal.
Palam recorded a maximum temperature of 33.5 degrees Celsius, 1.6 degrees below normal, while Lodi Road recorded 35.3 degrees Celsius, 2.3 degrees above normal.
The rise in pollution at the beginning of October comes as the city transitions out of the monsoon season, when changing wind patterns and atmospheric conditions can affect the dispersion and accumulation of pollutants. CREA has noted that wind speed, wind direction and atmospheric mixing, in addition to rainfall, play an important role in Delhi’s air quality.
