SF: The AQI reaches 245, its highest level in 100 days, as forecasts indicate poor air quality will persist through at least 23 October.
TBS Report
21 October, 2026, 08:35 pm
Last modified: 21 October, 2026, 08:50 pm
Delhi's air quality deteriorated to the poor category for the first time this season today (21 October), with the Air Quality Index (AQI) reaching 245, its highest level in 100 days, prompting authorities to activate the first stage of the capital's anti-pollution action plan.
The Commission for Air Quality Management (CAQM) activated Stage I of the Graded Response Action Plan (GRAP) across Delhi after the city's air quality slipped into the poor category.
The last time Delhi recorded a comparable AQI was on 13 July, when the index stood at 246, according to data.
The Air Quality Early Warning System has forecast that air quality is likely to remain poor until 23 October. Its outlook for the following six days also indicates that pollution levels will remain in the poor category.
According to the system, conditions are unfavourable for pollutant dispersion when the ventilation index falls below 6,000 square metres per second and average wind speeds remain below 10kmph.
The deterioration comes a day after Vijayadashami celebrations, during which large effigies of demon king Ravan were burnt at several locations across Delhi. However, no direct link has been established between the celebrations and the worsening air quality.
According to the Decision Support System for Air Quality Management in Delhi, the transport sector within the city was the largest contributor to pollution on Tuesday, accounting for 20.5% of emissions.
Stubble burning contributed up to 8%, while residential sources accounted for 5.2%, peripheral industries 4.3%, construction 2.8%, waste burning 1.8%, road dust 1.4% and other sources 1.3%.
India's Central Pollution Control Board classifies AQI readings of 0–50 as good, 51–100 as satisfactory, 101–200 as moderate, 201–300 as poor, 301–400 as very poor and 401–500 as severe.