10°C: Chilly Delhi on cold wave brink

The national capital continued to experience winter chill weeks ahead of “normal” schedule, with the minimum temperature on Tuesday lower than in several hill towns, pushing the city to the brink of its first early November “cold wave” in at least 30 years.

The national capital continued to experience winter chill weeks ahead of “normal” schedule, with the minimum temperature on Tuesday lower than in several hill towns, pushing the city to the brink of its first early November “cold wave” in at least 30 years.

A street hawker seen sitting next to a fire on a cold evening near Teen Murty bus stop, in New Delhi, India, on Monday, November 2, 2020. (Sanjeev Verma/HT photo)

Delhi’s minimum temperature, recorded at the Safdarjung observatory, which is considered the official reading for the city, was 10 degrees Celsius at 6:30am. This was lower than the minimum temperatures recorded in Dalhousie (10.9 degrees), Kasauli (10.7 degrees), Dharamsala (10.6 degrees), Kangra (10.2 degrees), and Mussoorie (10.4 degrees).

Scientists at the India Meteorological Department (IMD) said that the temperature is expected to remain around the 10-degree mark through the week. The minimum temperature has been hovering at 3-5 degrees below normal for the past five days.

A “cold wave” is when the minimum temperature 10 degrees Celsius or less, and 4.5 degrees less than normal for two consecutive days. Another chilly morning on Wednesday would officially put the city in the midst of a cold wave. Delhi’s minimum temperature on Monday was 10.8 degrees.

The normal minimum temperature for this part of the year is 14-15 degrees Celsius. Cold waves in Delhi are not unusual in November-end. But officials said there has been no cold wave in the first week of November in at least the last three decades.

Kuldeep Srivastava, the head of IMD’s regional weather forecasting centre, said temperatures dropping to such levels were highly unusual for Delhi and NCR towns at this time of the year.

“In Delhi, there has been no drastic change in the conditions that would trigger such a drop in the temperature. The only difference is that over the last two days because of a western disturbance, there was light rain and snow fall over Himachal Pradesh and Jammu & Kashmir. In the coming two days too, there is a forecast of light rain over Himachal Pradesh, Jammu & Kashmir and Uttarakhand. This will bring cold winds from these regions to Delhi and neighbouring cities, dropping the temperatures,” Srivastava said.

Other experts suggested that the signs pointed to an unusually cold winter.

“The winds are northwesterly, so cold air is blowing towards the plains from the Himalayas. But this is a La Nina year, and the circulation features are such that there is more cold air intrusion into the northern plains. We can expect a very cold winter this year,” said M Rajeevan, secretary, ministry of earth sciences.

La Nina, the cold phase of El Niño and the Southern Oscillation (Enso), is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean. According to the National Oceanic and Atmospheric Administration (NOAA), it is associated with strong monsoon, above average rains, and colder winters in India.