Global warming has changed the characteristics and scenario of cold patterns and cold day conditions in the country with an overall reduction in the intensity of cold waves.

The severity of cold spells has decreased compared to the pre-industrial era, said Dr Muhammad Abul Kalam Mallik, a meteorologist at Bangladesh Meteorological Department (BMD).

“The duration of mild cold wave is increasing but that of moderate to severe ones is decreasing day by day due to the global warming,” he said.

There are unusual characteristics that have turned the cold patterns, cold day conditions and shifting of the scenario into a mysterious situation in Bangladesh, said the meteorologist.

On Thursday, the mercury in Dhaka city dipped to as low as 12.8 degrees Celsius while the highest temperature was 18.2 degrees.

But the city dwellers were feeling a severe cold condition due to the low difference between the highest and lowest temperatures, Abul Kalam said.

The highest and lowest temperatures of Dhaka were 18.5 degrees and 13.1 degrees Celsius respectively on Wednesday.

“We recorded Dhaka’s lowest temperature at 6.5 degrees Celsius on 3 January 1995. Since then, the temperature rose gradually and people in Dhaka city didn’t witness any severe cold wave,” Abul Kalam said.

Dhaka city witnessed 7.2 degrees Celsius on 7 January 1983, 6.8 degrees on 13 January 1989, 7.2 degrees on 22 January 1993, 7.6 degrees on 21 January 1993, 6.5 degrees on 3 January 1995, 7.8 degree on 26 January 1997, 7.8 degree on 11 January 1998 and 7.2 degree Celsius on 13 January 2013, according to the BMD.

However, the minimum temperature of Dhaka city did not fall below 10 degrees Celsius in the last 10 years, said the meteorologist.

The lowest temperature in Dhaka city was 11.4 degrees Celsius on 11 January 2015, 10 degrees on 27 January 2016, 11.3 degrees on 17 January 2017, 9.5 degrees on 8 January 2018, 12 degrees on 5 January 2019, 11.3 degrees on 3 February 2020, 10 degrees on 1 February 2021 and 12.2 degrees Celsius on 8 February 2022, according to the BMD.

Though the mild cold wave is prevailing, people were feeling severe cold waves and chilly bites as the difference between day and night temperatures has reduced drastically accompanied by fog, wind from the northern direction and lack of sunlight.

The long duration of fog over Pakistan, India’s Delhi, Uttar Pradesh, Madhya Pradesh, Digha and West Bengal, Bangladesh and Myanmar is obstructing the sunlight from appearing, bringing the severe feeling of cold wave, said Abul Kalam.

The people were feeling a severe cold wave as day temperatures drastically fell to 11-16 degrees Celsius in the absence of the sunlight in the last couple of days in Dhaka and the last seven days in the northern and northwestern regions, he said.

“The cold wave will continue throughout the month but there’s no chance of a severe cold wave in the country,” said the meteorologist.

The lowest temperature in the country was 8 degrees Celsius in Dinajpur on Thursday.

The lowest temperature in the country was recorded at 2.6 degrees Celsius on 8 January 2018 in Tetulia, 2.8 degrees on 4 February 1968 in Sreemangal, 3.9 degrees on 1 January 1955 in Dinajpur, 3.6 degrees on 27 January 1964 in Ishwardi, 4.5 degrees on 11 February 1972 in Jashore and 4.5 degrees on 14 January 1978 in Bhola.