Dense fog in parts of Delhi, min temp at 7.1 deg C; 22 trains delayed

New Delhi: The national capital on Friday recorded a minimum temperature of 7.1 degrees Celsius, a notch below the season average, the weather department said.

Dense fog conditions prevailed in parts of the city with the Palam Observatory near the Indira Gandhi International Airport recording a visibility level of 50 metres at 5:30 am.

According to the Indian Railways, 22 Delhi-bound trains were delayed by one to six hours due to fog.

Very dense fog is when visibility is between 0 and 50 metres, between 51 and 200 metres is dense, between 201 and 500 metres moderate, and between 501 and 1,000 metres shallow.

According to the data by the Central Pollution Control Board (CPCB), the overall Air Quality Index (AQI) at 9 am stood at 347.

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.

The relative humidity at 8.30 am was 95 per cent, the IMD bulletin said.

The weather department has predicted a clear sky with very dense fog for Friday.

The maximum temperature is likely to settle around 19 degrees Celsius.