IMD issues 'yellow alert' for dense fog in the national capital

There is a possibility of dense fog on Friday morning, and the maximum and minimum temperatures are likely to hover around 18ºC and 7ºC respectively, the IMD (India Meteorological Department) said in New Delhi.

The weather department has issued a "yellow alert" for dense fog in the national capital and adjoining areas for the next two days.

Delhiites woke up to another foggy morning on Thursday as the minimum temperature settled at 6.6ºC, a notch below the season's average.

The maximum temperature was recorded at 18.6 degrees Celsius, a notch below the normal, an IMD bulletin said.

Eighteen trains bound for New Delhi were running late due to reduced visibility, according to officials concerned.

The IGI Airport witnessed dense fog with visibility ranging between 50 and 100 metres from 12.30 am to 6.30 am. It has now improved and currently, the visibility is 300 metres, the IMD said in a tweet.

According to the weather office, very dense fog is when visibility is between 0 and 50 metres, between 51 and 200 metres dense, between 201 and 500 metres moderate, and between 501 and 1,000 metres shallow.

As per data from the Central Pollution Control Board (CPCB), the 24-hour average air quality index (AQI) on Thursday settled at 318, which falls in the "very poor" category.

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 recorded at 5.30 pm was 72 per cent, the IMD bulletin said.