Delhi’s air slipped into the severe range on Monday 9 November, as the post-Diwali haze lingered over the Indian capital.
A live reading put Delhi’s air quality index (AQI) at about 370 to 404 on Monday morning, described as “severe,” based on PM2.5 — the fine particulate matter that penetrates deep into the lungs. That replaces the earlier reading of about 247, which no longer reflects conditions on Monday.
Yesterday’s readings were conflicted, with figures of 483 and a morning average of 383–384 reported. That conflict underlines why a single reading should not be treated as the day’s official figure without a CPCB check.
Diwali fireworks and winter haze
Diwali fireworks are a central part of the story. Fireworks add a sharp burst of particulate matter to air that is already thick with vehicle exhaust, construction dust and crop burning from neighbouring states, and the still winter air traps it over the city.
The Graded Response Action Plan (GRAP) measures, which restrict construction, vehicle use and industrial activity as pollution rises, are the government’s main tool for responding. GRAP Stage III is now in force, with the Commission for Air Quality Management ordering its measures as the AQI crossed into severe territory. Delhi’s education department has instructed schools to run hybrid classes for Classes 1 to 5 while the air stays severe.
For Delhi’s residents, the numbers translate into burning eyes, sore throats and difficulty breathing, and into advice to stay indoors, wear masks and avoid outdoor exercise. Children, older people and those with asthma or heart conditions are most at risk.
The haze is expected to linger while wind speeds stay low and temperatures fall overnight, trapping pollutants close to the ground. Until the wind picks up or rain clears the air, Delhi will remain in the “severe” range. Delhi was already the world’s most polluted city before Diwali, when the AQI hit 581.
