The Met Department said that Southwest monsoon conditions are getting established over the island.
Prevailing rainy conditions in the South-west part of the island is expected to enhance today (May 20).
Showers or thundershowers will occur at times in Western, Southern, Sabaragamuwa, Central and North-western provinces.
Very heavy falls, above 150 mm can be expected at some places in Sabaragamuwa province.
Meanwhile, windy conditions in the sea areas around the island and showery condition in the sea area to the South-west of the island are expected to enhance today.
Sea area extending from Puttalam to Kankasanthurai via Mannar and from Matara to Potuvil via Hambantota can be rough at times as the wind speed can increase up to 60 kmph.