Why winter bites despite no cold wave as fog narrows day, night temperatures

Morning fog has erased the sun from much of Bangladesh, leaving winter to bite deeper than expected. With the gap between day and night temperatures shrinking to near record lows, the cold is being felt more sharply -- even without a cold wave.

The Bangladesh Meteorological Department (BMD) has forecast that dense fog will persist for several more days, warning that temperatures could fall slightly over the next two days.

Meteorologist Shahnaz Sultana told bdnews24.com on Monday afternoon that although no cold wave was in effect, the chill was sharper because the difference between maximum and minimum temperatures had narrowed significantly, while persistent fog was blocking sunlight. 

“The intensity of this cold and the dominance of fog will continue for a few more days,” she said.

Explaining why the cold feels stronger than the actual readings, she said Dhaka’s minimum temperature early Monday was 13.8 °C, while the maximum reached only 15.5 °C. 

“That leaves a difference of just 1.7 degrees. When the gap between day and night temperatures drops to five degrees or less, the cold feels much more intense. With the difference now at 1.7 degrees, the chill is being felt far more strongly,” she said.

She added that dense fog has prevented sunlight from reaching the ground, reducing surface heating and further intensifying the cold. The foggy conditions, she said, are likely to persist nationwide for at least two more days.

In the 24 hours up to 6am on Monday, the country’s lowest temperature -- 10 °C -- was recorded at Nikli in Kishoreganj, while the highest temperature of 28.6 °C was logged in Teknaf.

In its five-day forecast, the Met Office said skies from Monday to Friday may remain temporarily partly cloudy, with dry weather prevailing across the country.

From midnight to morning during this period, moderate to dense fog may form in parts of the country, with fog lingering until noon in some areas. 

From Monday to Wednesday, dense fog could temporarily disrupt air traffic, inland water transport and road communications, while the cold may feel more severe in many regions.

The Met Office said night temperatures on Monday may fall slightly, with daytime temperatures remaining almost unchanged. 

On Tuesday, both night and day temperatures may decline nationwide, before edging up slightly on Wednesday and Thursday. Temperatures are expected to remain largely unchanged on Friday.