New Delhi, Jan 10 (IANS): Cold wave conditions eased in Delhi on Tuesday due to a fresh western disturbance affecting northwest India, however dense fog lowered visibility to just 50 metres, affecting surface and air traffic movement.

At Safdarjung observatory, the minimum temperature of 6.4 degrees Celsius was recorded in the morning while the weather stations at Lodhi Road, Ayanagar and Ridge recorded a minimum temperature of 6.4 degrees, 4.2 degrees and 4.3 degrees, respectively.

Due to the very dense fog, around 39 trains were delayed by two to five hours, as per the officials.

"Visibility (in meter) recorded at 0530 hours IST of 10.01.2023: Bhatinda and Agra - 0 each. Jammu division, Ganganagar, Chandigarh, Ambala, Patiala, Bareilly, Lucknow, Sultanpur, Gorakhpur and Bhagalpur - 25 each. Hissar, Delhi-Palam, Baharaich, Gaya, Purnea and Kailashahar - 50," said India Meteorological Department in a tweet.

"As forecasted, Dense to very dense fog observed over parts of Punjab, Northwest Rajasthan, Jammu division, Haryana, Chandigarh & Delhi, Uttar Pradesh, Bihar and Tripura," IMD said in another tweet.

Meanwhile, the overall air quality in the national capital was recorded in 'severe category' at 461 on Tuesday morning, according to the System of Air Quality and Weather Forecasting And Research (SAFAR).

The AQI at Pusa, Delhi University, Lodhi Road and Ayanagar was recorded at 465, 429, 444 and 493, all in the 'severe category' on Tuesday morning.

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