Showers or thundershowers are expected at several locations in the Western, Sabaragamuwa and Southern provinces, as well as in the Nuwara Eliya District, after 1 p.m., the Department of Meteorology said.
Mainly dry weather will prevail across other parts of the island, it said.
The public is advised to take precautions to minimize potential damage from temporary localized strong winds and lightning during thundershowers.
Atmospheric conditions are expected to become favorable for evening thundershowers in most parts of the island from April 20 onward, the Met Department said.
Showers or thundershowers are likely at a few locations in sea areas off the coast, extending from Mannar to Hambantota via Colombo and Galle.
Winds will be south-easterly or variable in direction, with speeds of 20-30 km/h.
Sea conditions are expected to be slight.
However, temporarily strong gusty winds and very rough seas may occur during thundershowers, the Department warned. (Newswire)