Dense fog blankets northern India with no respite from cold wave, visibility drops to zero

New Delhi: Northern India woke up to thick fog on Sunday, facing cold wave conditions as visibility dropped to zero at several places including Delhi.
According to the India Meteorological Department (IMD), visibility was recorded as 'zero for the first time this winter season in Sri Ganganagar in Rajasthan, Patiala, Ambala, Chandigarh, Palam, Safdarjung (New Delhi), Bareilly, Lucknow, Bahraich, Varanasi, Prayagraj, and Tezpur.
The national capital shivered in the cold weather, with the average minimum temperature dropping to almost 3 degrees Celsius on Sunday morning.
The minimum temperature in Delhi's Safdarjung area was recorded at 3.5 degrees Celsius. Similarly, the minimum temperature in Palam was 5.9 degrees Celsius, 3.4 degrees Celsius in Lodhi Road, 4.0 in Ayanagar, and 4.4 degrees Celsius in Ridge at 8:30 am.
As per IMD data at 5:30 am today, very dense fog was observed in isolated parts of Punjab, Haryana, Delhi, Bihar, and East Uttar Pradesh, while dense fog conditions were observed in isolated parts of Jammu, Chandigarh, West Uttar Pradesh, Assam, and South Interior Karnataka.
As per IMD data, visibility was recorded below 200 meters in Jammu division, Punjab, Delhi, West Uttar Pradesh, Bihar, Assam, and Tripura on Sunday morning.
Also, moderate fog was observed in Tripura, Andhra Pradesh, and Tamil Nadu.
Following dense fog conditions in the national capital, the Delhi police advised commuters to drive slowly and maintain proper distance.
The traffic was impaired in several parts of Delhi as thick fog caused low visibility.
More than 20 passenger trains were delayed due to dense fog and low visibility in the national capital.
According to Northern Railways, three trains are delayed by around six hours, namely Amritsar-Nanded Express, Katihar-Amritsar Express, and Jammutawi-Ajmer Pooja Express.
At least four trains are running late by 3-3.30 hours, including Azamgarh-Delhi Kaifiyat Express, Puri-New Delhi Purushottam Express, Rewa-Anand Vihar Express, and Kamakhya-Delhi Junction Btahmputra Express, as per the railways' data.
Further, according to the railways, four Delhi-bound trains, namely Prayagraj-New Delhi Express, Ambedkarnagar-Katra, Hyderabad-New Delhi Express, and Manikpur-Nizamuddin Express, are running behind schedule by around 2-2.30 hours.
In addition to these, as many as 11 trains are running late by around 1-1.30 hours. This included Kanpur-New Delhi Shramshakti Express, Saharsa-New Delhi Vaishali Express, Rajendranagar-New Delhi Express, Pratapgarh-Delhi Junction, Indore-New Delhi, Vasco-Nizamuddin, Chennai-New Delhi, Ferozpur-Mumbai Express, Amritsar-Mumbai Mail, and Bikaner-Delhi Sarai Rohilla Express.
Delhi airport authorities also issued an advisory for flyers following dense fog in the region.
The flight operations are likely to get affected due to the fog, airport officials said.
Departure of a Delhi-Pune flight of Vistara airline was also delayed by about an hour on Sunday due to dense fog and poor visibility.
As per the airport officials, dense fog conditions continue to prevail in the region, causing zero visibility, and the Runway Visual Range (RVR) at all four runways continues to remain at 50 to 100 meters.
CAT III-B has been operational, they said.
A CAT III-B is an automated system that helps with a precision approach and landing when the runway visibility is at a distance no less than 50 feet (15m) and is at a visual range that is less than 200 meters and most certainly not less than 50 meters.
The condition is likely to continue for the next two to three hours, they said.
The Air Quality Index (AQI) across Delhi dipped into the 'severe' category in several areas as per the Central Pollution Control Board (CPCB) amid the cold weather conditions.
AQI in Anand Vihar was recorded at 478, in JLN at 465, in IGI Airport (T3) at 465, and in ITO Delhi at 455.