Delhi's 24-hour average air quality index, which was 379 at 4 pm, breached the 400 mark around 10 pm amid extremely calm winds and "buildup of an inversion layer adversely affecting the vertical mixing height".

GRAP-4 was enforced in Delhi in November due to high pollution, but on December 5, the SC allowed the CAQM to relax it to Stage 2 as air quality improved.

NCR, Stage IV of the Graded Response Action Plan (GRAP) has been activated. This step was taken after the Air Quality Index (AQI) slipped into the 'Severe' category. GRAP-IV mandates stringent measures,

A Central air quality panel for Delhi-NCR invoked GRAP III on Monday afternoon following a sharp rise in pollution levels. The national capital recorded a minimum temperature of 4.5 degrees Celsius on Monday morning while the AQI dipped to the 'very poor' category — reaching 367 by 2 pm.

Amid rising pollution levels, Delhi-NCR has imposed Stage 4 air quality measures, halting construction activities, enforcing hybrid school modes, and restricting non-essential diesel trucks. The 24-hour AQI exceeded 400,

The Commission for Air Quality Management (CAQM) on Monday invoked GRAP III in the Delhi-National Capital Region (NCR) after sharp rise in pollution levels.

The Graded Response Action Plan Level-III (GRAP-III) restrictions were reimposed in Delhi and the national capital region due to "highly unfavourable meteorological conditions," including low wind speeds and very low mixing height.

Due to further poor air quality, schools across Delhi NCR will implement a hybrid learning model for up to grade 5, as per the GRAP-III guidelines. This decision followed the enforcement of the measures of GRAP-III by the Commission for Air Quality Management because of "very unfavourable weather conditions like calm wind and very low mixing height".

GRAP was activated for the first time in Delhi in October this year when air quality crossed the 300-degree mark. As the city is shrouded in smog, these actions aim to reduce the negative impact of air pollution on public health and the environment.

GRAP-4 was enforced in Delhi in November due to high pollution, but on December 5, the SC allowed the CAQM to relax it to Stage 2 as air quality improved.

Delhi's air quality plummeted, triggering the implementation of GRAP Stage-IV ('Severe+') restrictions across the NCR. The AQI soared past 400, prompting an emergency CAQM meeting. Schools have responded by reverting to hybrid learning for students up to Class V,