As Delhi braces for the festive season, its residents are once again grappling with the familiar and alarming sight of hazy skies. Even before the onset of winter and the lighting of Diwali firecrackers, the capital’s air quality has begun to deteriorate sharply. On Thursday, October 16, 2025, the city recorded an Air Quality Index (AQI) of 237, placing it firmly in the ‘poor’ category for the third consecutive day. The worsening trend, typically expected in the weeks following Diwali, has arrived earlier than usual this year, sparking concerns among environmental authorities and meteorologists alike.

Meteorologists attribute the current dip in air quality primarily to low wind speeds, high humidity, and shallow fog — conditions that trap pollutants closer to the ground. These factors have combined to create a stagnant atmosphere over the National Capital Region (NCR), allowing dust, vehicular emissions, and other suspended particles to accumulate. As a result, even without the influence of winter inversion layers or post-harvest stubble burning at its peak, Delhi’s air has turned increasingly toxic.

Mahesh Palawat, Vice President of Meteorology and Climate Change at Skymet Weather, explained that the present meteorological conditions are highly unfavorable for the dispersion of pollutants. “Daytime temperature will increase, but there will be low wind speeds and a slight haze in the morning. These factors are reducing visibility and contributing to poor air quality,” he said. “Meteorological conditions will, overall, remain unfavourable in the next few days.”

According to the data released by the Central Pollution Control Board (CPCB), the AQI stood at 201 on Tuesday, 210 on Wednesday, and 237 on Thursday — showing a steady deterioration. The numbers place Delhi’s air firmly in the ‘poor’ category, meaning that prolonged exposure could cause respiratory discomfort to sensitive groups, including children, the elderly, and those with pre-existing lung conditions. The trend points toward a gradual worsening of air quality in the days ahead.

The India Meteorological Department (IMD) has predicted that the minimum temperature in Delhi on Thursday will hover around 18.1 degrees Celsius, with a maximum of 32.5 degrees Celsius. The city recorded a relative humidity level of 87 percent in the morning, accompanied by mist and light fog that persisted until late morning. No rainfall has been forecast, further reducing the likelihood of any natural cleansing of pollutants from the atmosphere. Clearer skies during the day are offering little relief, as the pollutants remain suspended due to weak winds and lack of vertical mixing in the air.

The Centre’s Air Quality Early Warning System (EWS) for Delhi, in its recent forecast, warned that the air quality is likely to remain in the ‘poor’ category from October 16 to 18. The outlook for the subsequent week indicates a further decline, with the AQI expected to slip into the ‘very poor’ category by October 20 and 21. This projection comes just as the city prepares for Diwali celebrations, a period typically associated with a sharp surge in particulate matter due to firecracker use and crop residue burning in neighboring states.

While stubble burning has not yet reached its seasonal peak, satellite data indicates an uptick in early-stage agricultural residue fires in Punjab and Haryana. Experts caution that as temperatures dip and the winds weaken further, emissions from these fires will begin drifting toward Delhi, compounding the existing pollution burden. Combined with vehicular emissions, industrial discharge, construction dust, and the impending use of firecrackers, the cumulative impact could push Delhi’s air quality into the ‘severe’ zone in the weeks to come.

Recognizing the early signs of a worsening air crisis, the Commission for Air Quality Management (CAQM) in NCR and Adjoining Areas convened an emergency meeting earlier this week. In light of the deteriorating conditions, it invoked Stage-I measures under the Graded Response Action Plan (GRAP) with immediate effect across the entire NCR. The GRAP, a graded system of emergency responses, is activated when air quality begins to breach specific thresholds. Stage-I measures include a ban on garbage burning, tighter controls on dust emissions from construction sites, enhanced mechanized road cleaning, and increased frequency of water sprinkling to curb particulate matter.

A senior CAQM official noted that the early invocation of GRAP is a preventive measure designed to slow the progression of pollution levels. “We are entering a critical period where atmospheric conditions are unfavorable. Immediate enforcement of Stage-I actions can help mitigate some of the impact before we reach severe levels,” the official said.

Meanwhile, the Delhi government is exploring longer-term and experimental solutions to combat the city’s chronic pollution problem. One of its most ambitious initiatives this year is the plan for artificial rain through cloud seeding. In September, the Delhi government signed a Memorandum of Understanding (MoU) with the Indian Institute of Technology (IIT) Kanpur for five cloud seeding trials. The trials aim to induce rainfall, which could help settle airborne pollutants and improve visibility.

Environment Minister Manjinder Singh Sirsa announced on Wednesday that Delhi’s first-ever artificial rain trial will likely take place after Diwali, pending clearance from the Indian Meteorological Department (IMD). “Pilots have already completed trial flights over the designated areas, and the aircraft are fully equipped for the process. The crew is trained and familiar with the region,” Sirsa confirmed. He added that the cloud seeding operations will be conducted in northwest Delhi, where meteorological conditions are most conducive for successful rainfall induction.

Cloud seeding, though not a permanent fix, has been viewed as a temporary relief measure in several pollution-hit cities across the world. However, experts caution that its effectiveness depends heavily on existing cloud cover and atmospheric moisture — both of which can be unpredictable. Nonetheless, the experiment reflects Delhi’s growing urgency to explore unconventional solutions in the face of persistent and worsening air quality challenges.

Delhi’s pollution crisis has been a recurring feature each autumn and winter, driven by a combination of natural and anthropogenic factors. The city’s topography, characterized by a landlocked basin surrounded by industrial belts, exacerbates the problem by limiting the dispersal of pollutants. Seasonal changes, agricultural burning, increased vehicular use during festivals, and cooler temperatures collectively trap emissions close to the surface. Despite repeated interventions, the capital continues to rank among the world’s most polluted urban centers during this period.

Experts emphasize that while meteorological conditions play a major role in worsening air quality, the underlying issue remains human activity — particularly unchecked emissions. Unless structural changes are made to reduce dependence on fossil fuels, improve public transport, and strictly enforce industrial norms, the annual pattern of smog and respiratory distress is unlikely to end. As Delhi enters yet another pollution season, the onus lies equally on policymakers and citizens to take concerted action to safeguard public health.

For now, as the haze thickens and air quality slides deeper into the ‘poor’ zone, the city stands on the brink of another environmental emergency — one that has become an all-too-familiar prelude to winter in the national capital.