Delhi’s air quality deteriorated to an AQI of 166 on October 1, marking the most polluted start to the month in four years as low wind speeds limited the dispersal of pollutants across the capital. The reading remained in the moderate category, but experts warned that stagnant atmospheric conditions could allow pollution levels to rise.
The Central Pollution Control Board’s data showed that 37 of Delhi’s 44 monitoring stations recorded air quality in the moderate category. Five stations reported poor air quality, while two recorded satisfactory conditions. The citywide average placed Delhi’s AQI at 166 on Thursday.
The October 1 reading was the highest recorded for the date since 2022, when Delhi’s AQI stood at 186. The comparison indicates a more polluted start to October than in the previous two years, although the current reading remains below the poor category under the national air-quality classification system.
Delhi’s Air Quality Early Warning System forecast that the AQI would remain in the moderate category from October 2 to October 4. It also projected that air quality would remain between moderate and satisfactory during the following six days. The forecast is subject to changes in wind speed and local atmospheric conditions.
Experts cited low wind speed and unfavourable conditions for the dispersion of pollutants as factors that could contribute to further accumulation. The early warning system identifies a ventilation index below 6,000 square metres per second and average wind speeds below 10 kilometres per hour as conditions that are unfavourable for pollutant dispersal. When these conditions persist, emissions from traffic, construction, road dust and other urban sources can remain concentrated near the surface.
Ground-level conditions were visible in parts of the city, including flying dust near Mundka on Rohtak Road. The observation adds a local dimension to the monitoring data, as road and construction dust can affect air quality in neighbourhoods even when the citywide average remains in the moderate range.
Weather conditions in Delhi were otherwise described as normal on Thursday. The maximum temperature was 35.2 degrees Celsius, 0.5 degrees above normal, while the minimum temperature was 24 degrees Celsius, 0.7 degrees above normal. Relative humidity ranged from 42 to 91 per cent. The forecast for Friday indicated clear skies, with a maximum temperature of 34 degrees and a minimum of 23 degrees Celsius.
The immediate air-quality outlook remains dependent on ventilation conditions. The Early Warning System’s forecast is for moderate to satisfactory air quality over the coming days, while the next significant shift will be determined by changes in wind speed, pollutant dispersion and local emissions.
