Delhi’s air quality enters ‘severe’ category, AQI breaches 400

Delhi’s air quality deteriorated into the “severe” zone — the worst grade on the government’s pollution scale— on Friday morning, with a thick, smoky haze continuing to envelop the Capital.

According to HT’s real-time air quality dashboard and the Central Pollution Control Board (CPCB), Air Quality Index (AQI) stood at 403 at 7.30am, 82 points higher than the previous 24 hours.

Delhi last recorded severe air quality on January 19, when the AQI stood at 410.

CPCB classifies an AQI 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”.

HT reported earlier that Delhi’s air quality deteriorated sharply on Thursday, with the city’s PM2.5 concentration more than doubling in 24 hours to 244 micrograms per cubic metre by 6pm — four times the national standard. Calm wind conditions persisted at Safdarjung throughout Thursday night, with all 11 observations between 8pm and 6.30am recording still air. The lack of wind limited the dispersion of pollutants, allowing them to accumulate overnight

According to HT’s dashboard, 32 of the 59 reporting stations were in the severe category and PM2.5 was the leading pollutant at 48 of the city's 58 monitoring stations.

NASA's satellite detected 4,107 farm fires in Punjab and Haryana from October 1 to November 12 (Punjab: 3,729; Haryana: 378), with 96 on November 12. Over the same dates last season, it counted 4,220.

According to HT's analysis, burning has shifted later each year (98% of the fire heat Meteosat recorded in 2025 occurred after 3pm, compared with 94% in 2024), so the two counts can differ for that reason alone. Both are undercounts because most of the burning now occurs after the satellite passes at about 1.45pm.

According to HT’s dashboard, 32 of the 59 reporting stations were in the severe category, with IIT Delhi recording the highest rating of 488.