Delhi continued to face significant environmental challenges on Tuesday morning, with the Air Quality Index (AQI) registering 385, keeping the city in the ‘very poor’ category. Dense fog enveloped the capital, significantly reducing visibility and prompting warnings from the India Meteorological Department (IMD) and airlines.

Air Quality and Visibility

As of 6 am, visibility across Delhi was reported at just 350 metres, according to the IMD. The city’s air quality had slightly improved from Monday’s 24-hour average AQI of 401, which was classified as ‘severe.’ Despite the marginal improvement, the persistent smog and low visibility continued to pose health risks, particularly for vulnerable populations such as children, the elderly, and those with respiratory issues.

The IMD issued a red alert for dense fog in Delhi, Haryana, Punjab, Chandigarh, Uttar Pradesh, and parts of the Northeast, East, and North India. The dense fog is expected to persist during early mornings, with marginal improvement in intensity later in the day. Wind conditions are expected to improve slightly, which may aid in dispersing pollutants and reducing fog density.

Impact on Flights and Travel Advisory

The dense fog has severely impacted air travel. IndiGo Airlines issued a travel advisory warning passengers of potential flight disruptions due to low visibility, affecting Delhi as well as other northern and eastern cities including Chandigarh, Amritsar, Ranchi, and Kolkata. Air India issued a similar advisory, highlighting possible delays and cancellations.

Despite these warnings, Delhi Airport reported that flight operations were running smoothly on Tuesday morning as visibility improved somewhat. Nevertheless, travelers were advised to monitor flight schedules closely and allow additional time for check-in and security procedures.

Fog Alerts and Temperature Details

The Regional Meteorological Department issued an orange and yellow alert for Delhi on Tuesday, reflecting areas of moderate to dense fog. South, northeast, and central Delhi were placed under an orange alert, while west, northwest, and north Delhi received a yellow alert. Early morning temperatures hovered around 10 degrees Celsius, contributing to the dense fog formation.

Health and Environmental Concerns

Delhi’s air quality has been a persistent concern this month, with December 2025 on track to become the most polluted since 2018. The average AQI for the month until December 29 stood at 349, compared to 360 in December 2018. The prolonged poor air quality is attributed to a combination of industrial emissions, vehicular pollution, and stagnant weather conditions that trap pollutants in the atmosphere.

The IMD and health authorities have urged residents to limit outdoor activities, use masks if venturing out, and maintain adequate hydration. Vulnerable groups are particularly advised to stay indoors during peak fog hours in the early morning and late evening.

Previous Day’s Disruptions

On Monday, flight operations at Indira Gandhi International (IGI) Airport were heavily affected, with over 550 flights delayed, 130 cancelled, and several diverted due to low visibility. The fog also impacted road travel and contributed to traffic congestion in several parts of the city.

Outlook for the Coming Days

While the intensity of the fog may marginally reduce on Tuesday, dense conditions are expected to continue during early mornings until January 1. The IMD forecasts slightly better wind conditions later in the day, which may help in the partial dispersion of pollutants and improve overall air quality. However, residents are advised to remain cautious and adhere to safety guidelines during periods of dense fog.

In summary, Delhi faces a challenging start to the year with severe air pollution compounded by dense fog. Authorities have issued alerts, and airlines have cautioned travelers, but health and safety measures remain critical as the city navigates this period of environmental stress.