Some 33,000 Rohingya refugees from Myanmar, controversially displaced to a storm-prone island in the Bay of Bengal, have also been asked to remain inland.
Cyclones, such as hurricanes in the North Atlantic or typhoons in the Northwest Pacific, are a common and fatal risk on the northern coast of the Indian Ocean, home to tens of millions of people.
But scientists say climate change is likely making them more intense and frequent, and Bangladesh is already ranked by the UN as one of the countries hardest hit by extreme weather events since the turn of the century.
Cyclone Sitrang, with gusts of 88 kilometers (55 miles) consistent with the hour, is expected to make landfall near the city of Khepupara in southern Bangladesh on Tuesday morning, the weather bureau said.
Most worrisome for the government is the typhoon’s storm surge forecast up to 3 meters (10 feet) above overall tidal levels, which could flood spaces that are home to millions of people.
Officials in the coastal districts of Patuakhali, Bhola, Barguna and Jhalakathi told AFP that up to 400,000 more people would be evacuated from vulnerable villages and islands to shelters.
“We have a plan to evacuate about 250,000 people. There are 703 cyclone shelters in the district and many multi-storey buildings. We will complete the evacuation tonight,” Patuakhali district administrator Kamal Hossain told AFP.
The Red Crescent Society has mobilized tens of thousands of volunteers to use loudspeakers to alert others and villagers to evacuate, spokesman Shahinur Rahman told AFP.
The new sediment island of Bhashan Char, where Bangladesh has displaced Rohingya refugees to overcrowded camps, is also expected to be affected by heavy rains and strong winds.
“The shelters at Bhashan Char are across a 19-foot-high embankment. Even so, we asked other people to stay at home,” a senior security official on the island told AFP.
In the neighboring Indian state of West Bengal, several thousand people have also been evacuated as a precaution, with more than a hundred rescue centers open, officials said.
“A special is watching 24 hours along the coast of the state,” West Bengal Government Minister Arup Biswas said.
“Fishermen have been asked not to venture into the sea. The ferries have also been suspended,” he said.
In 2020, Cyclone Amphan, the “super cyclone” moment ever recorded over the Bay of Bengal, killed more than a hundred people in Bangladesh and India, and affected millions.
Last year, more than a million people were evacuated along India’s east coast before Cyclone Yaas battered the region with winds of up to 155 kilometers per hour, becoming a Category 2 hurricane.
Cyclone Bhola in 1970, one of the world’s worst herbal disasters, killed several hundred thousand people in Bangladesh, then known as East Pakistan, and India.
In recent years, greater foresight and greater efficiency in the preparation of evacuation plans have especially reduced the number of victims of these storms.