More than 30,000 people belonging to some 9,000 families have been affected by the adverse weather conditions prevalent across the island over the past few days, the Disaster Management Centre (DMC) said.
According to the Department of Meteorology, the daily downpours are likely to continue.
Showers or thundershowers will occur at various intervals in the Eastern, Uva and Central provinces and the Polonnaruwa and Hambantota districts, with several spells of showers expected in the Northern province and the Anuradhapura district, the Met Department said.
Showers or thundershowers are forecast to occur elsewehere in the island after 1 pm.
Heavy rains above 100mm are likely in the Trincomalee, Batticaloa, Ampara, Polonnaruwa, Nuwara-Eliya, Badulla and Monaragala districts and the Sabaragamuwa and Western provinces.
Fairly heavy showers about 75-100 mm are also expected in parts of the Galle, Matara, Hambanthota, Matale and Kandy districts, the Met Department added.
Meanwhile, the Army has carried out an operation to assist GCE Ordinary Level (O/L) candidates in Kilinochchi affected by floods, the Army said.
Army personnel helped more than 150 students reach their examination centres using tractors and boats.
Troops also assisted the school authorities in rescuing submerged furniture, the Army said.