Cyclone Mahasan has weakened into a tropical storm, causing far less damage than had been feared as it passed over Bangladesh and sparing Burma almost entirely.
At least 18 deaths related to Mahasen were reported in Bangladesh, Burma and Sri Lanka, but officials had prepared for a far greater storm.
Bangladesh evacuated one million people from coastal areas and the United Nations warned that 8.2 million people could face life-threatening conditions.
The cyclone lost power as it shed huge amounts of rainfall and then veered west of its predicted path, sparing major Bangladeshi population areas, including Chittagong and Cox's Bazar, said Mohammad Shah Alam, director of the Bangladesh Meteorological Department.
"Thank God we have been spared this time," local government administrator Ruhul Amin said.
The storm's impact in Burma, where officials were having trouble evacuating tens of thousands of displaced Rohingya people, was minimal.
"We are out of danger and the impact of the cyclone is almost over. There can be heavy rains in some areas because of the cyclone, but the danger is over," said Tun Lwin, the retired director general of Burma's meteorology department.
Earlier river ferries and boat services has been suspended, and scores of factories near the choppy Bay of Bengal were closed. Tens of thousands of people fled their shanty homes along the coast and packed into cyclone shelters, schools, government office buildings and hotels.
A 1991 cyclone that slammed into Bangladesh from the Bay of Bengal killed an estimated 139,000 people and left millions homeless. In 2008, Burma's southern delta was devastated by Cyclone Nargis, which swept away entire farming villages and killed more than 130,000 people.