New Delhi, Dec 20 || Delhi-NCR woke up to a thick blanket of fog on Saturday, with the India Meteorological Department issuing an orange alert for dense fog conditions expected to persist through the day.
"Partly cloudy sky. Dense to very dense fog during morning hours. Mist/shallow fog during night/early hours," the IMD said in its forecast for the national capital.
The weather department explained that "very dense fog" is recorded when visibility drops to between 0 and 50 metres, while visibility of 51 to 200 metres is categorised as "dense".
Visibility between 201 and 500 metres falls under the category of "moderate" fog, and visibility between 501 and 1,000 metres is termed "shallow" fog.
Alongside the poor visibility, Delhi continued to grapple with severe air pollution. The Air Quality Index remained in the "very poor" category at 376 as of 6:00 a.m., according to data from the Central Pollution Control Board.
The Air Quality Early Warning System has forecast that pollution levels are likely to worsen further, with the AQI expected to enter the 400-plus "severe" category over the weekend.