Delhi recorded its worst post-Dussehra air quality in five years on Wednesday, as the Air Quality Index (AQI) climbed to 245 as per the Central Pollution Control Board (CPCB), pushing the capital into the ‘poor’ category for the first time this season.However, as per AQI.in the numbers were above 300 and continued to hover in the same margin on Thursday as well.The AQI was recorded at 358 at 08:00 am on Thursday, indicating the effect of Dussehra fireworks continues to dominate the air.On October 20, the Central Pollution Control Board (CPCB) recorded an AQI of 179 at 4 pm, which rose to 245 at 4 pm the following day, on Wednesday, October 21. A layer of smog engulfs the India Gate, in New Delhi, Oct.

21, 2026. The deterioration prompted the Commission for Air Quality Management (CAQM) to invoke Stage I of the Graded Response Action Plan (GRAP) across Delhi-NCR, enforcing strict measures to try and keep the air from getting worse than it already is.WHY IS DELHI SO POLLUTED?The spike in AQI followed Dussehra celebrations, when firecrackers and the burning of effigies released smoke and fine particles into the air.

But the problem is more nuanced than simply blaming the deterioration on the festival alone. Weather conditions also influence how quickly pollution builds up.

An effigy goes up in flames during Dussehra festival celebrations, in New Delhi. Light winds can allow pollutants to accumulate instead of carrying them away, while falling temperatures and changes in the movement of air can further affect how well pollution disperses.Vehicle exhaust, road dust, construction activity and industrial emissions continue to add to Delhi's pollution load.

Then there is the smoke from crop-residue burning in neighbouring states that can also contribute, depending on wind direction and weather conditions.#WATCH | Delhi: The Air Quality Index (AQI) in the area around India Gate is 238, categorised as 'Poor', as per the CPCB (Central Pollution Control Board). Visuals from the area this morning https://t.co/ThuNYfIzC0— ANI (@ANI) October 22, 2026The Air Quality Early Warning System, run by the Indian Institute of Tropical Meteorology (IITM), forecast that Delhi's air would remain in the poor category from October 21-24.Under Stage I of GRAP, authorities must strengthen dust-control measures, prevent open burning of waste, enforce pollution checks on vehicles and step up action against other sources of emissions.A POLLUTED START TO OCTOBERThe latest deterioration comes as Delhi tries to find its footing in battling the annual pollution problem, as the capital had a hazy and unfavourable start to October.

An anti-smog gun truck sprays water on a road to curb dust pollution in New Delhi. Earlier in the month, Delhi's average AQI between October 1-4 stood at 174.5, the highest for those four days since 2020, trumping the average of 119.75 in 2025 and 167.25 in 2024.On October 4, Delhi's AQI reached 187, its highest level in 83 days at the time.The rise followed a brief spell of cleaner air in September, when rain and stronger winds helped disperse pollutants, allowing Delhi to breathe easy as the monthly average AQI came in at 102, its lowest September average in five years.Delhi's fine-particle pollution has risen about a fifth since early October, and CPCB data shows its dirtiest hours come around midnight.