Dense fog, low sunshine bring cold wave-like chill countrywide

Parts of the country, including Dhaka, have been experiencing cold wave-like chilling weather for the last four days due to reduced sunshine during winter caused by persistent fog, meteorologists said on Monday.

According to the Bangladesh Meteorological Department (BMD), the fog sweeping across the country has significantly shortened the duration of sunshine, leading to a sharp fall in temperature and heightened cold conditions.

Meteorologists attributed the unusual fog to rising pollution levels, including air pollution, as well as the impacts of climate change, citing findings from a recent BMD study.

The country's lowest temperature was recorded at 10°C in Nikli amid a mild cold wave, while Dhaka recorded a maximum temperature of 15.5°C and a minimum of 13.8°C on Monday, the met office said.

According to the BMD classification, a mild cold wave occurs when temperatures fall between 8.1°C and 10.0°C, moderate between 6.1°C and 8.0°C, severe between 4.1°C and 6.0°C, and very severe below 4.0°C.

"The fog we are experiencing usually develops in early January and lasts for about four days, and up to a week in the northern districts. But this year it has arrived in late December due to shortened sunshine hours caused by dense fog," said Md Bazlur Rashid, a meteorologist at the BMD and one of the authors of the study.

He explained that increasing air pollution and climate change are contributing to fog formation, which in turn is making people feel cold wave-like conditions.

Following December 25, temperatures have fallen sharply across the country, he said. "We are seeing a sudden drop in temperature-from around 28°C to 13-14°C-which is quite significant."

The met office also noted that day and night temperatures are currently remaining almost similar, intensifying the feeling of cold across the country.

Similar weather patterns are being observed in parts of India, including New Delhi and Uttar Pradesh, due to changing climate conditions, Rashid added.

The BMD warned that thick fog may disrupt air navigation, inland river transport and road communication. The prevailing situation may continue for a few more days, although rainfall or strong winds could help improve conditions by clearing the fog.

Meanwhile, hospitals across the country are witnessing a rise in patients suffering from cold-related illnesses, particularly among children and the elderly.

Dr Sadia Sultana Reshma, a specialist at the National Institute of Diseases of the Chest and Hospital (NIDCH), told The Financial Express that dry air and increased pollution during winter are accelerating the spread of airborne diseases.

"A large number of patients are being admitted with lung infections and breathing difficulties caused by severe air pollution," she said, adding that around 1,500 patients visit the NIDCH outdoor department daily, while 50-60 are admitted to indoor wards on average.

As temperatures dropped, people were seen flocking to roadside temporary stalls and shopping malls to buy warm clothes over the weekend. Crowds were observed at makeshift roadside shops in areas such as Gulistan, Shahjadpur, Badda, Purana Paltan and around the Baitul Mukarram National Mosque.

Md Monirul Islam, a roadside vendor in Shahjadpur, said demand for winter clothing has surged over the last four to five days. "Sweaters, jackets, children's warm clothes, caps and socks are selling fast, mostly priced between Tk 200 and Tk 500," he said.

In its 24-hour forecast issued on Tuesday, the met office said weather may remain dry with temporarily partly cloudy skies across the country. Moderate to thick fog may occur in many areas from midnight to morning and could persist until noon in some places.

Night temperatures may fall by 1.0-2.0°C, while day temperatures may fall slightly, and cold conditions are likely to persist due to fog, the BMD said. With a similar outlook for the next five days, both day and night temperatures may fall further towards the end of the period.

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