All of Sri Lanka and large parts of Indonesia, southern Thailand and northern Malaysia have been hit by heavy and prolonged rains. Many residents have been forced to cling to rooftops while awaiting rescue and entire villages have been isolated.
In Indonesia, at least 502 people have died and hundreds are missing. The country's President Prabowo Subianto said on Monday that he hoped the worst was over. He has come under increasing pressure to declare a national emergency over the situation.
Warship
The government has sent three warships with emergency aid and two hospital ships to some of the worst-hit areas where roads have become impassable.
Sri Lanka has requested help from other countries and deployed military helicopters to reach people stranded. At least 340 people have died there and many more are missing. In Colombo, floodwaters are reported to have reached their peak and there are hopes that they will begin to recede. The water that came as a surprise to many residents near the capital.
Every year we experience minor floods, but this is something different, says resident Dinusha Sanjaya.
It's not just the amount of water, but how quickly it all happened.
Monsoon season
At least 176 people have died in southern Thailand, authorities said on Monday. Two deaths were reported from Malaysia.
Much of Asia is now in its annual monsoon season, which often brings heavy rain, triggering landslides and flooding.
The floods that have hit Indonesia, Thailand and Malaysia have been exacerbated this year by a rare tropical storm, particularly on the island of Sumatra.
