The Department of Meteorology has forecast a week of sustained heavy rainfall across south-western Sri Lanka, warning of significant flooding risk in coastal and inland areas through May 29, 2026.
Rainfall is expected to range between 30mm and 50mm daily from May 24 to 26, with some locations receiving up to 100mm during this period. Intensity is forecast to sharpen on May 27, when widespread heavy showers exceeding 80mm are expected across much of the region.
The peak is forecast for May 28, when the broadest spread of heavy rain is anticipated, raising the risk of waterlogging and flooding in low-lying areas. Rainfall is expected to persist at 50mm to 80mm on May 29 before easing.
The districts most likely to be worst affected are Galle, Matara, Kalutara and Ratnapura. Residents in coastal and inland communities have been urged to take advance precautions, particularly those living in flood-prone areas.
The forecast comes as Sri Lanka continues to grapple with the early onset of the South-West Monsoon. The monsoon has already claimed one life and affected over 27,000 people across six districts as of May 23, with flood warnings active on the Kalu and Attanagalu river basins. The Meteorology Department has also issued a week-long heavy rain advisory for the south-west with a peak on May 28.
NBRO has placed Kegalle and Ratnapura districts on Red alert for landslide risk at multiple divisional secretariat divisions, with further heavy rain now forecast to compound the threat through the coming days.
