Showers will occur at times in the Northern, North-central, Central, Uva, Eastern and Southern provinces, the Department of Meteorology said.
Fairly heavy rainfall exceeding 75 mm is likely at some places in the Eastern and Uva provinces and in the Polonnaruwa, Matale and Nuwara Eliya districts.
Showers or thundershowers are expected at several places elsewhere after 1.00 p.m.
Misty conditions may prevail in parts of the Central and Sabaragamuwa provinces, as well as in the Galle and Matara districts during the early morning hours.
The public has been advised to take adequate precautions to minimise damage caused by temporary localised strong winds and lightning during thundershowers.