Delhi's minimum temperature rose by a degree at most locations across the national Capital on Thursday, even as dense fog persisted for nearly six hours. Early-morning foggy weather in north and northeast India has heavily impacted road, rail and air traffic over the last fortnight. The minimum temperature was settled at 6.6 degrees Celsius, one notch below the season's average.
There is a possibility of dense fog on Friday morning and the maximum and minimum temperatures are likely to hover around 18.6 degrees Celsius, a notch below the normal , the India Meteorological Department (IMD) said . The moderate sunlight gave much relief in the day time from the icy winds. The weather department has issued a "yellow alert" for dense fog in the national capital and adjoining areas for the next two days.
The IMD said visibility at the Delhi airport oscillated between 50 and 100 metres between 12:30am and 6:30am, impacting flight operations. However, it improved to 350 metres by 8:30 am. Due to foggy conditions, over 50 flights being delayed during that period, and at least five flights were cancelled in the early hours of the day. The maximum temperature was recorded in Palam 17.2 degrees Celsius, Lodhi Road 17.4 degrees Celsius, Ridge 17.8 degrees Celsius, Ayanagar 18.4 degrees Celsius, Jafarpur 16.2 degrees Celsius, Narela 16.1 degrees Celsius, SPS Mayur Vihar 14.2 degrees Celsius and Pusa 19.3 degrees Celsius.
Meanwhile, at least 18 trains- either originating from or bound for the capital, were delayed by over one hour. Several flights were delayed due to fog at airports. Delhi had recorded five cold wave days between Friday and Tuesday, with the minimum temperature recorded below 4°C on all five days. Mercury has risen by nearly three degrees in the last 48 hours, owing to warm easterly blowing towards the national Capital. Delhi's minimum on Tuesday was 3.5°C and it was 5.7°C on Wednesday.
A layer of fog lowered visibility to zero metres at several places in north and northeast India, affecting rail traffic, officials said. Satellite imagery showed some reduction in fog over Bihar and eastern Uttar Pradesh.
However, 'dense' to 'very dense' fog prevailed in parts of Punjab, Haryana, west Rajasthan, Bihar, Delhi, west Uttar Pradesh, Jharkhand, Odisha and Assam.
In the plains, the MeT office declares a 'cold wave' if the minimum temperature dips to 4 degrees Celsius or when the minimum temperature is 10 degrees or below and is four-and-a-half notches below the normal. A 'severe cold wave' is when the minimum temperature dips to 2 degrees Celsius or the departure from the normal is by more than 6.4 degrees.
A 'cold day' is when the minimum temperature is less than or equal to 10 degrees Celsius below normal and the maximum temperature is at least 4.5 degrees below normal. A 'severe cold day' is when the maximum is 6.5 degrees Celsius or more below normal.