Delhi-NCR: Stricter pollution control measures under Stage 4 of the Graded Response Action Plan (GRAP) have been enforced in the Delhi-NCR region as air quality plummeted to the “severe” category on Saturday evening, January 17, 2026. The Commission for Air Quality Management (CAQM), which oversees pollution mitigation in the National Capital Region, made the announcement following a sharp deterioration in air quality after a brief period of relative improvement earlier in the month.

The move to enforce GRAP Stage 4 came a day after the imposition of Stage 3 restrictions, underscoring the rapid worsening of atmospheric conditions in the region. According to CAQM officials, Delhi’s 24-hour average Air Quality Index (AQI) was recorded at 354 on Saturday, categorised as “very poor.” By 6 pm, the AQI had surged to 416, entering the “severe” category, a level that signals serious health risks to all sections of the population.

The GRAP framework is designed to enforce pollution mitigation measures based on the severity of air quality. Under the system, air quality is classified as poor (AQI 201–300), very poor (301–400), severe (401–450), and severe plus (above 450). Each stage triggers a set of regulatory actions, ranging from restrictions on construction and industrial activity to curbs on vehicular movement and enforcement of anti-burning measures. Stage 4, the strictest category currently in effect, involves heightened restrictions on construction, suspension of certain industrial activities, and intensified monitoring of pollutant sources.

Factors Driving the Severe Pollution Spike

Meteorological conditions, seasonal factors, and human activities have combined to produce dangerously high pollution levels. Dense fog in the early mornings has exacerbated the situation, turning into thick smog as smoke and particulate matter accumulated in the stagnant air. Experts note that during winter, cooler temperatures and low wind speeds often trap pollutants close to the ground, creating a stable atmospheric layer that prevents dispersal.

A senior official cited by PTI explained, “Forecasts indicate that due to slow wind speed, stable atmosphere, unfavourable weather parameters, and lack of dispersal of pollutants, Delhi’s average AQI is likely to breach the 400-mark and enter the severe category in the coming days.” These conditions were compounded by typical winter emissions, including vehicular exhaust, industrial output, biomass burning in nearby regions, and firecracker residue from recent festivities.

The India Meteorological Department (IMD) recorded a minimum temperature of 4.4 degrees Celsius on Saturday in the national capital, which is 3.2 degrees below the seasonal average. This extreme winter chill has further contributed to the persistence of dense fog layers, limiting visibility and exacerbating the pollution crisis. The maximum temperature, however, recorded at 24.6 degrees Celsius, was five degrees above the seasonal average, suggesting wide diurnal temperature fluctuations typical of north Indian winters.

Mahesh Palawat of Skymet Weather, a private weather forecasting agency, said that while minimum temperatures are expected to gradually rise between January 17 and 20, another cold spell is forecast between January 23 and 26, which could bring temperatures down again and worsen air quality. Light winter rainfall activity is also expected over the coming days, which may offer temporary relief by reducing particulate matter in the atmosphere, but the overall pollution load remains high.

Implications of GRAP-4 Enforcement

With the enforcement of GRAP Stage 4, authorities in Delhi and the NCR region have intensified measures to curb pollution. These include:

• Suspension of construction activities in the NCR region, except for emergency projects.
• Restrictions on industrial units that fail to meet emissions standards.
• Enforcement of stringent anti-burning measures, targeting stubble burning in neighbouring states such as Punjab and Haryana.
• Regulation of vehicular movement, including increased monitoring of non-compliant vehicles contributing to particulate emissions.
• Increased deployment of monitoring teams to track compliance with emission standards across factories, power plants, and other potential sources of air pollution.

Public health advisories have also been issued, with authorities urging residents, particularly vulnerable populations such as children, the elderly, and those with respiratory conditions, to limit outdoor activity. The “severe” AQI level poses health risks to all residents, with potential impacts including respiratory distress, irritation of the eyes and throat, and exacerbation of pre-existing cardiovascular and respiratory conditions.

Historical Context and Challenges

Delhi and the surrounding NCR region face recurring winter pollution crises, often exacerbated by a combination of local emissions, industrial output, vehicular traffic, and transboundary pollution from stubble burning in neighbouring states. The implementation of the GRAP system, initiated in 2017, was aimed at providing a structured, stage-wise response to worsening air quality, ensuring that regulatory measures are scaled according to the severity of pollution.

While GRAP has provided a framework for mitigation, challenges remain in enforcement and compliance. Industrial units, construction activities, and vehicular traffic contribute significantly to the pollution load, and curbing emissions requires coordinated action across multiple jurisdictions. Seasonal agricultural practices, particularly stubble burning, also pose a major challenge, as smoke from crop residue drifts into Delhi-NCR during winter months, compounding local pollution.

Public Response and Health Measures

Residents across Delhi and the NCR have expressed concern over the deteriorating air quality. Many reported experiencing breathing difficulties, irritation of the eyes and throat, and general discomfort due to the thick smog that blanketed the city. Schools and outdoor activity organizers have been advised to limit exposure for children, while healthcare facilities are on alert for a potential increase in cases related to respiratory distress.

Authorities have also emphasized the importance of personal preventive measures, including the use of masks capable of filtering fine particulate matter, avoiding strenuous outdoor activity, and keeping windows closed during peak pollution hours. Hospitals and clinics in the region have reported an increase in patients with respiratory issues over the past few days, reflecting the tangible health impacts of the severe pollution episode.

Looking Ahead

As the winter season continues, meteorologists and environmental experts warn that the Delhi-NCR region could experience further spikes in pollution if weather conditions remain unfavourable and emissions are not controlled. The combination of slow wind speeds, low temperatures, and persistent fog creates an environment conducive to pollutant accumulation.

The CAQM and other authorities continue to monitor air quality in real-time and are prepared to enforce higher stages of GRAP if the AQI rises further. Public awareness campaigns, enforcement of anti-burning regulations, and coordinated efforts among state governments in the region are crucial to mitigating the crisis.

While temporary relief may come from weather changes, such as light winter rainfall or increased wind speeds, experts stress that long-term solutions require stricter enforcement of emission norms, reduction in vehicular pollution, adoption of cleaner fuels, and cooperation from neighbouring states to curb stubble burning.

Conclusion

The enforcement of GRAP Stage 4 in Delhi-NCR serves as a stark reminder of the severity of the city’s winter pollution problem. With air quality reaching the “severe” category, authorities and residents face an urgent public health challenge. Coordinated measures, both immediate and long-term, are essential to protect the health of millions and to gradually reduce the persistent pollution that plagues the region during winter months.

The coming days will be critical in determining whether the stringent restrictions under GRAP-4, combined with favourable weather conditions, can bring relief to residents of Delhi and the National Capital Region. Meanwhile, the public is urged to take all possible precautions to minimize exposure to hazardous air and follow official advisories diligently.