Heavy rains have been lashing at least 13 of the 25 administrative districts since last Friday, inundating several villages, hospitals and government offices, Disaster Management Centre said today.
The five deaths were recorded in the eastern districts of Batticaloa and Ampara and in the south western region of Embilipitiya.
"Two women died after the taxi they were travelling in was caught in a tidal wave of flash floods at Embilipitiya while three others drowned," police said.
In October, dozens of people were killed when mudslides buried homes of tea plantation workers in the country's central hills.