Delhi may witness the longest and severest “cold day” spell this month in 22 years as the India Meteorological Department predicted “cold day to severe cold day” conditions on Tuesday. In December 1997, the national Capital had recorded 17 cold days and a 13-day cold spell, a senior weather department official said.

Kuldeep Srivastava, the head of the department’s regional forecasting centre, said that a “cold day” is declared when the maximum temperature goes at least 4.5 degrees below normal. A “severe cold day” is recorded when the highest temperature goes below 6.5 degrees Celsius.

A “cold day” classification is used when the maximum temperature, or day temperature, dips below a specific mark. A cold wave is declared after the night temperature plunges. Srivastava said that Delhi had witnessed eight straight cold days or a cold spell as of now. In December 2014, an eight-day cold spell was recorded, he added.

“Cold day to severe cold day conditions very likely in many pockets over Punjab, Haryana,
Chandigarh and Delhi and Uttar Pradesh; in some pockets over Bihar and in isolated pockets over Uttarakhand and cold day in isolated pockets over Himachal Pradesh, Rajasthan and Sub-Himalayan West Bengal and Sikkim,” the met department’s afternoon bulletin on Tuesday said.

Such conditions along with “dense to very dense fog in the morning hours” is likely to prevail in the next few days, the department said. “The severe cold day conditions are likely to continue for the next few days, Srivastava told The Times of India. “Night temperatures are likely to gradually dip as well and touch 4 degrees Celsius by December 28.”

The weather official attributed the weather conditions to the heavy snowfall in the hills between December 12 and 13, adding that icy north-northwesterly winds in Delhi followed soon after moderate rain. December 17 was the coldest December day in 22 years as the maximum temperature was recorded at 12.2 degrees Celsius in Safdarjung. In 1997, the lowest temperature in the same period was 11.3 degrees Celsius.

Among parts of northern India, Kashmir recorded intense cold conditions on Tuesday as minimum temperatures in the Union Territory and Ladakh were below several degrees than the freezing point due to clear skies. The city of Srinagar witnessed the coldest night of the season with the minimum temperature at -4 degrees Celsius on Monday night – more than four degrees below Sunday night’s temperature.

Meanwhile, the Central Pollution Control Board recorded overall pollution levels at 375 in the “very poor” category as of 1 pm on Tuesday while the real-time air quality index was recorded at 342, according to System for Air Quality and Weather Forecasting and Research or SAFAR. The CPCB index typically differs from that of SAFAR because it averages values for 24 hours.