As the festive lights of Diwali illuminated the night sky, a dense haze began to descend upon Delhi, dimming the city’s celebratory glow with a thick curtain of pollution. On Monday, October 20, 2025, the capital’s Air Quality Index (AQI) took a sharp plunge into the “very poor” category, underscoring the city’s chronic battle between tradition and environmental sustainability. Despite warnings from authorities and restrictions under the Graded Response Action Plan (GRAP) Stage II, firecrackers once again dominated the Diwali celebrations, leaving Delhi’s air choked with toxic particles and the population bracing for worsening conditions in the days ahead.

According to data released by the Central Pollution Control Board (CPCB), Delhi’s overall AQI stood at 345 by 6 p.m. on Diwali day—well within the “very poor” range. Out of the city’s 38 air quality monitoring stations, 34 recorded pollution levels in the “red zone,” reflecting concentrations of harmful particulate matter that pose significant health risks. Environmental experts noted that the air quality had already been deteriorating in the days leading up to Diwali due to seasonal factors such as low wind speed, temperature inversion, and crop residue burning in neighboring states. The bursting of even so-called “green firecrackers” only accelerated the decline.

A City Engulfed in Toxic Air

By Monday morning, air pollution readings across Delhi painted a grim picture. Most monitoring stations registered AQI values above 300, signifying “very poor” air quality. Anand Vihar, one of the city’s most polluted areas, recorded the highest AQI of 414 at 6 a.m., crossing into the “severe” category. Wazirpur followed closely with readings of 419 later in the day. Even relatively cleaner locations like Sri Aurobindo Marg struggled to stay below 200, with readings around 158 to 168 during the day. These numbers indicated that almost every corner of the capital was enveloped in smog.

Residents reported reduced visibility, eye irritation, and breathing discomfort throughout the day. Commuters traveling to work on Monday morning described the roads as “hazy” and “smoke-filled,” while health experts cautioned vulnerable groups—such as children, the elderly, and those with respiratory illnesses—to limit outdoor activities. Doctors from several city hospitals reported a noticeable increase in patients complaining of wheezing, coughing, and throat irritation within hours of Diwali night celebrations.

GRAP Stage II Comes into Effect

To combat the alarming rise in pollution, the Commission for Air Quality Management (CAQM) enforced Stage II restrictions under the Graded Response Action Plan (GRAP) across Delhi-NCR from Sunday evening, October 19. This move followed the implementation of Stage I measures earlier in mid-October, as the air quality had already begun to slip into the “poor” category. GRAP is a set of emergency response strategies designed to tackle air pollution based on severity levels, ranging from Stage I (Poor) to Stage IV (Severe+).

Under GRAP Stage II, several key restrictions were imposed. Diesel generator sets—except those used for essential services such as hospitals and emergency operations—were banned across the NCR. The number of non-compliant interstate buses entering Delhi was reduced, and authorities increased parking fees across the city to discourage the use of private vehicles. Municipal bodies were directed to intensify mechanical road sweeping and water sprinkling to minimize dust re-suspension, while construction activities generating dust were closely monitored.

Despite these measures, officials acknowledged that enforcement challenges remain a major obstacle. Firecracker violations were reported from multiple parts of the city, with many residents ignoring the restrictions and continuing to burst fireworks late into the night. Local police and pollution control authorities confirmed receiving hundreds of complaints, but limited manpower and widespread non-compliance made it difficult to take swift action in every case.

The Debate Over Green Firecrackers

One of the most contentious issues this Diwali was the use of “green firecrackers.” The Supreme Court had earlier allowed their sale and bursting under strict conditions, citing the need to balance festive traditions with environmental concerns. Green firecrackers are designed to emit 30–40% less particulate matter and noise compared to conventional ones. However, environmentalists argue that while these variants are relatively safer, their large-scale use still contributes significantly to short-term pollution spikes.

The court’s directive permitted the bursting of green firecrackers within specific time windows—6 a.m. to 7 p.m. and 8 p.m. to 10 p.m.—on the day before Diwali and on Diwali night itself. Yet, reports from several areas indicated that fireworks continued well beyond the permitted hours. This widespread non-compliance, combined with unfavorable weather conditions, exacerbated the pollution levels and caused the AQI to remain elevated even into the following morning.

Environmental experts also questioned the authenticity of many “green” firecrackers available in the market. Several environmental groups alleged that counterfeit products—sold under the guise of being eco-friendly—contained similar chemical compositions as banned varieties. The Delhi Pollution Control Committee (DPCC) has reportedly initiated investigations into such cases, warning of strict penalties for manufacturers and sellers found violating the norms.

Meteorological Conditions Worsen the Situation

While human activities played a central role in the pollution surge, meteorological conditions in Delhi amplified the impact. The India Meteorological Department (IMD) reported that the maximum temperature on Diwali day was 33.3°C, slightly above the seasonal average, while the minimum temperature stood at 20.6°C—2.2 degrees higher than normal. The higher nighttime temperature, coupled with low wind speed and increased humidity, prevented pollutants from dispersing, effectively trapping them close to the ground.

Experts noted that such weather patterns are typical for this time of year, as the transition from monsoon to winter leads to weaker air circulation. This natural stagnation, when combined with emissions from vehicles, construction, stubble burning, and firecrackers, creates a perfect storm for smog formation. Meteorologists warned that the situation was likely to deteriorate further in the next 48 hours, as calm winds and a drop in temperature were expected to reduce dispersion even more.

Health and Policy Concerns

The deteriorating air quality once again sparked debates over Delhi’s long-standing struggle with pollution control and environmental governance. Despite repeated court orders, public awareness campaigns, and regulatory measures, the capital continues to witness a sharp spike in pollution every year during and after Diwali. Health experts emphasize that short-term exposure to such high pollution levels can cause severe respiratory distress, particularly for individuals with asthma or chronic obstructive pulmonary disease (COPD). Prolonged exposure, they warn, could lead to long-term cardiovascular and neurological effects.

Policy analysts argue that Delhi’s air pollution crisis cannot be addressed in isolation. The city’s geographic location and its proximity to industrial and agricultural regions in Haryana, Punjab, and Uttar Pradesh make it vulnerable to transboundary pollution. Crop residue burning in these neighboring states contributes heavily to the particulate matter load in the air during October and November. While efforts have been made to promote alternatives such as bio-decomposers and machinery for residue management, progress remains uneven.

Looking Ahead

As Delhi wakes up to the aftermath of another cracker-filled Diwali, the immediate focus now shifts to mitigation. Civic authorities have intensified road-cleaning operations and dust suppression efforts, while health advisories have urged citizens to wear masks, use air purifiers indoors, and avoid strenuous outdoor activities. However, environmentalists insist that without behavioral change and stricter enforcement, these short-term measures will offer little relief.

Delhi’s recurring post-Diwali smog serves as a reminder of the urgent need for sustained policy action and collective responsibility. While cultural traditions and festive enthusiasm remain integral to India’s social fabric, the capital’s worsening air quality has become a public health emergency that demands immediate, coordinated, and science-based solutions. For now, the city’s skyline glows not only with lights of celebration but also with the dim, lingering haze of an environmental crisis that refuses to fade.