The Department of Meteorology says the highest rainfall in the island during the past 24 hours was recorded from Kotapola, Matara.
The area experienced showers of 149 mm.
It added that Deniyaya, Neluwa and Kudawa also experienced strong showers above 100 mm yesterday.
The Department said the prevailing windy condition is expected to enhance further in the western and southern seas and in the southern half of the island due to the active Southwest Monsoon.
It predicted showers in the Western, Sabaragamuwa and North-Western provinces and in Kandy, Nuwara-Eliya, Galle and Matara districts.
Heavy showers above 100 mm are expected in Sabaragamuwa province and in Kandy, Nuwara-Eliya, Galle and Matara districts.