Delhi woke up on Sunday, December 28, 2025, to dense fog, cold wave-like conditions, and a sharp deterioration in air quality, as the national capital’s Air Quality Index (AQI) approached the brink of the “severe” category. Data from the Central Pollution Control Board (CPCB) Sameer app indicated that Delhi’s AQI stood at 391 at 6:05 am, placing it firmly in the “very poor” bracket. Meanwhile, nearby Noida recorded an AQI of 415, crossing into the “severe” category, highlighting the continuing intensity of winter pollution in the National Capital Region (NCR).

The combination of meteorological factors—dense fog, low wind speeds, and cold temperatures—alongside local emissions from vehicles, industries, and construction, has exacerbated pollution levels. The India Meteorological Department (IMD) issued a yellow alert for Sunday morning, warning residents about reduced visibility and cold wave conditions, which are expected to persist in the coming days.

Air Quality Breakdown Across Delhi

The CPCB monitors air quality through 40 stations across the city, 39 of which were active on Sunday morning. Of these, 20 stations recorded “severe” air quality readings. Key hotspots included:

• Anand Vihar: AQI 445
• Chandni Chowk: AQI 415
• Jahangirpuri: AQI 430
• Shadipur: AQI 443
• Wazirpur: AQI 443

Other stations registered AQI levels between 301 and 400, falling under the “very poor” category, while NSIT Dwarka recorded a comparatively lower AQI of 214, classified as “poor.”

The CPCB categorises AQI as follows:

• 51–100: Satisfactory
• 101–200: Moderate
• 201–300: Poor
• 301–400: Very Poor
• Above 400: Severe

With Delhi hovering near the threshold of 400, the city is facing conditions that are not only harmful for vulnerable populations but also pose significant health risks for the general public.

Meteorological Factors Driving Pollution

Experts attribute the worsening air quality to a combination of weather patterns and emissions. Mahesh Palawat, vice president at Skymet, a private weather forecasting company, explained that wind speeds remained extremely low on Saturday, averaging around 4–5 kmph. For brief periods in the afternoon, winds reached 8–9 kmph, but the overall calm conditions allowed pollutants to accumulate close to the ground, creating dense smog.

“This pattern is expected to continue till January 1, 2026, due to the influence of a western disturbance,” Palawat said. Low winds and temperature inversions during winter prevent pollutants from dispersing, causing persistent haze and elevated PM2.5 and PM10 concentrations across the NCR.

Dense fog and reduced visibility not only contribute to environmental health risks but also affect daily life and transportation. Drivers, pedestrians, and public transport users face challenges navigating the city safely under such conditions.

Impact on Air Travel: Flight Delays at IGI Airport

The adverse weather conditions at Delhi also disrupted air travel, with FlightRadar24 data showing that over 150 flights were delayed at Indira Gandhi International (IGI) Airport on Sunday morning. Reduced visibility due to dense fog prompted air traffic controllers to impose temporary restrictions, resulting in a backlog of flights.

The airport issued an advisory at 9 am, reassuring passengers that flight operations were running smoothly as visibility improved. It encouraged travelers to check with airlines or the official airport website for the latest updates. The advisory also noted that airport staff were available across terminals to assist passengers and provide necessary support during delays.

Air Quality Outlook for the Coming Days

The Air Quality Early Warning System for Delhi (AQEWS) predicts that the city’s air quality will remain “very poor” in the immediate future. The bulletin forecasted that AQI levels are likely to stay in the “very poor” category from Sunday to Tuesday, with similar conditions expected over the following six days.

While GRAP (Graded Response Action Plan) Stage IV restrictions had been relaxed the previous Wednesday, stages one to three remain active. This includes measures such as limiting construction activities, controlling dust from demolition, and monitoring industrial emissions. Experts stress that although some curbs are in place, vehicular emissions continue to contribute significantly to the air quality crisis.

Health Implications of Prolonged Pollution Exposure

Air pollution at “very poor” and “severe” levels poses significant health risks. Particulate matter (PM2.5 and PM10) can penetrate deep into the lungs, causing respiratory problems such as asthma, bronchitis, and other chronic lung diseases. Short-term exposure can trigger eye irritation, coughing, and throat discomfort, while prolonged exposure may exacerbate cardiovascular conditions. Children, the elderly, and individuals with pre-existing health conditions are particularly vulnerable.

Authorities urge residents to minimize outdoor activities, especially during early morning and late evening when pollutant concentrations are highest. Wearing N95 or equivalent masks, using air purifiers indoors, and keeping windows and doors closed during peak pollution hours are recommended preventive measures.

Government Measures and Public Response

In response to persistent air quality deterioration, the Delhi government has implemented a series of measures under GRAP, including traffic restrictions for non-essential vehicles, suspension of construction activities during peak pollution days, and the promotion of clean fuel standards.

Despite these interventions, citizens continue to face challenges during winter pollution episodes. Dense fog further compounds risks for commuters, while low wind speeds make it difficult for pollutants to disperse naturally. Public awareness campaigns have been intensified, with authorities urging residents to limit private vehicle use, avoid burning waste, and adopt environmentally friendly practices wherever possible.

Looking Ahead: The Role of Weather and Policy

Experts note that while weather conditions are a significant driver of pollution spikes, consistent enforcement of GRAP measures and stricter compliance with emission standards are crucial to mitigating Delhi’s long-term air quality issues. Transitioning to cleaner fuels, promoting electric vehicles, and expanding public transport networks are seen as essential strategies to reduce vehicular emissions, which remain a primary source of pollution in the city.

Meteorologists predict that the influence of the western disturbance will keep temperatures low and wind speeds slow in the NCR for the next few days, likely prolonging the period of very poor air quality. Residents are advised to stay updated on real-time AQI readings and follow government advisories to safeguard health.

Conclusion

Delhi’s air pollution crisis continues unabated as dense fog, low wind speeds, and winter temperature inversions keep the city’s AQI hovering near the “severe” category. Early Sunday morning, over 150 flights at IGI Airport were delayed, while residents woke up to smog and poor visibility, highlighting the intersection of environmental and logistical challenges.

With the AQEWS forecasting continued “very poor” air quality for at least the next week, Delhiites face a period of heightened vulnerability. While government measures under GRAP provide partial mitigation, sustained efforts, public compliance, and strategic long-term planning are critical to address the recurring winter pollution problem. In the meantime, residents are urged to take precautions, limit outdoor exposure, and monitor official advisories to navigate the city safely during this season of dense smog and rising pollution levels.