The warning, issued at noon, will remain in effect until 11.30 PM.
According to the department, thundershowers accompanied by severe lightning are likely to occur in parts of the Western, Sabaragamuwa, Central, Uva, Northern, North-Central, Southern and North-Western provinces, as well as the Trincomalee District, after 1.00 PM.
The department also warned that temporary localized strong winds may occur during thundershowers.
The public has been urged to take necessary precautions to minimize damage and risks caused by lightning activity.
