Minimum temp falls to lowest in 3 weeks

A sharp deterioration in Delhi's air quality on Thursday - with the Air Quality Index (AQI) worsening by 60 points in just 24 hours - forced authorities to invoke Stage 3 of the Graded Response Action Plan (Grap), effectively bringing back restriction on old private four wheelers and banning private construction and demolition (C&D) across the National Capital Region (NCR).

- HT Correspondent

NEW DELHI:

The 24-hour average AQI, recorded at 4pm by the Central Pollution Control Board (CPCB), stood at 357, a "very poor" category reading.

This marked a significant drop from Wednesday's AQI of 297, which was categorised as "poor."

On December 5, the Supreme Court had directed CAQM to invoke Stage 3 of Grap when the AQI crosses 350, as compared to its earlier threshold of 400. Similarly, Stage 4 will have to be invoked when the AQI hits 400, the apex court had said.

CAQM, which held a meeting earlier in the day, said the average AQI was showing a rising trend, with meteorological conditions to remain adverse due to calm winds.