Delhi Faces 9-Hour Zero Visibility As Dense Fog Disrupts Flights, Trains; AQI Plummets

As dense fog continued to shroud Delhi, at least six flights were cancelled, and 95 others were delayed today. The city experienced an unprecedented nine-hour period of zero visibility on Saturday, marking the longest spell this winter season.

At 8 am, six flights were reported cancelled, and 114 delayed, with an average delay of 18 minutes at Delhi's Indira Gandhi International (IGI) Airport, according to flight tracking website Flightradar. On Saturday, 48 flights were cancelled, and 564 delayed at the IGI Airport.

Photo Credit: PTI

The India Meteorological Department (IMD) reported that the temperature dropped to 10°C at 5:30 am on Sunday, compared to 10.2°C at the same time on Saturday.

Delhi's pollution levels remained in the 'poor' category, with the Air Quality Index (AQI) recorded at 377 at 6 am today, according to Central Pollution Control Board (CPCB) data.

The dense fog caused disruptions to rail services as well, with 81 trains delayed and 15 flights diverted on Saturday, as reported by PTI citing officials.

"Zero visibility prevailed for nine hours at Palam between 6 pm and 3 am (UTC), marking the longest spell of the season. The city's primary weather station, Safdarjung, recorded eight hours of zero visibility," PTI quoted IMD officials as saying.

The maximum temperature in the city settled at 20°C, 0.7°C above the seasonal average, while the minimum temperature was recorded at 7.8°C, 0.9°C above normal, according to IMD. Relative humidity during the day ranged from 96% to 100%, it added.

For Sunday, the IMD forecast a partly cloudy sky with smog and moderate fog likely across most areas, and dense fog expected in a few places during the morning. "The predominant surface wind will blow from the southeast at a speed of less than 4 kmph during the morning hours," it stated.

The wind speed is expected to increase to 8-10 kmph from the southeast in the afternoon before dropping to less than 6 kmph in the evening and night. Smog or shallow to moderate fog is likely during the evening and night, it said.

The maximum and minimum temperatures are expected to be around 18°C and 10°C, respectively.

At 7 am on Saturday, visibility at IGI Airport was zero due to very dense fog. The Runway Visual Range (RVR) on its runways ranged between 100 and 250 metres under CAT III conditions.

"Such very dense fog with zero visibility under CAT III conditions has prevailed at the airport since 11:30 pm on Friday," the Met Office reported.

"While landings and take-offs continue at Delhi airport, flights that are not CAT III compliant may be affected. Passengers are requested to contact the concerned airline for updated flight information. Any inconvenience caused is deeply regretted," the Delhi International Airport Limited, which operates the airport, posted on X at 6:56 am.

The CAT III facility enables aircraft to operate in low-visibility conditions.

The Northern Railway reported that 59 trains were running late by up to six hours, while 22 were delayed by approximately eight hours.

In related news, Delhi's air quality remained in the 'very poor' category, with the 24-hour average AQI recorded at 378, according to CPCB data.

An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor', and 401-500 'severe'.