Delhi Imposes Stage 4 Restrictions Amid Severe Air Quality Crisis

Delhi is facing a severe air quality crisis, leading to the implementation of Stage 4 restrictions under the Graded Response Action Plan. With the Air Quality Index reaching alarming levels, the Commission for Air Quality Management has taken decisive actions, including banning trucks and halting construction activities. The situation is exacerbated by various factors, including stubble burning and vehicular emissions. This article delves into the measures being enforced to combat the pollution crisis and the implications for residents in the region.

By Narendra Chaudhary Jan 18, 2026, 08:43 IST

Severe Air Quality Triggers Stage 4 Measures

On Saturday, the Commission for Air Quality Management enacted Stage 4 restrictions under the Graded Response Action Plan (GRAP) to combat pollution in Delhi and the surrounding National Capital Region (NCR), as air quality levels fell into the 'severe' category.

The day prior, the commission had already implemented Stage 3 measures.

GRAP consists of a series of escalating anti-pollution strategies that are activated to prevent further deterioration of air quality once it reaches a specific threshold in the Delhi-NCR area. Established in 2020, the commission is a statutory body tasked with addressing pollution in the NCR and nearby regions.

As of Saturday, the Air Quality Index (AQI) in Delhi was recorded at 400 at 4 PM, worsening to 428 by 8 PM due to calm winds, a stable atmosphere, and unfavorable meteorological conditions that trapped pollutants.

The India Meteorological Department and the Indian Institute of Technology-Madras have predicted further declines in air quality, according to the commission.

To mitigate further air quality degradation, the GRAP sub-committee decided to proactively implement all actions under Stage 4.

An AQI classified as 'severe' indicates hazardous pollution levels that can pose significant health risks even to healthy individuals.

Stage 4 restrictions include a ban on trucks entering the region and a suspension of construction activities for both public and private projects. Schools, except for classes 10 and 12, will also transition to a hybrid learning model.

Previously enacted Stage 3 measures included a prohibition on non-essential construction work and the closure of stone crushers and mining operations.

Moreover, the use of BS-III petrol and BS-IV diesel vehicles is restricted in Delhi and the NCR.

BS norms, or Bharat Stage Emission Standards, are regulations established by the Indian government to limit air pollutants from vehicles. The higher the BS norm, the stricter the standards and the lower the allowable emissions.

The commission's decision on Saturday coincided with an overall AQI of 400 in Delhi, as reported by the Sameer application, which provides hourly updates from the Central Pollution Control Board.

On Sunday morning, the AQI in the national capital reached 439 at 7:05 AM.

An AQI value between 0 and 50 signifies 'good' air quality, while values from 51 to 100 indicate 'satisfactory' conditions. An AQI of 101 to 200 is considered 'moderate', and as the index increases, air quality worsens. Values from 201 to 300 are classified as 'poor', while those between 301 and 400 indicate 'very poor' air quality.

Values between 401 and 450 are categorized as 'severe', and anything above 450 is labeled as 'severe plus'.

Since mid-October, Delhi and its neighboring cities have consistently recorded air quality in the 'poor' or worse categories.

Air quality in Delhi typically deteriorates sharply during the winter months, often ranking as the world's most polluted capital. Contributing factors include stubble burning in Punjab and Haryana, vehicular emissions, firecracker usage during Diwali, lower temperatures, reduced wind speeds, and emissions from industries and coal-fired power plants.

On December 24, the commission lifted Stage 4 restrictions that had been imposed on December 13 after air quality fell into the 'severe plus' category.