Malaysia Braces for Persistent Thunderstorms and Heavy Rainfall Through the Conclusion of May

Thunderstorms and flash flood risks are set to continue in Malaysia through May. Climatologists explain the inter-monsoon peak affecting the west coast.

By: AXL Media

Published: Apr 21, 2026, 10:03 AM EDT

Source: Information for this report was sourced from The Straits Times

Inter-Monsoon Atmospheric Conditions Trigger Prolonged Wet Spell

Malaysia is facing an extended period of volatile weather as meteorologists predict that heavy rains and thunderstorms will continue to batter the region for several more weeks. According to Emeritus Professor Fredolin Tangang, a prominent climatologist, these conditions are typical for the current inter-monsoon phase, which officially commenced on March 29. The atmospheric setup is particularly conducive to intense precipitation during the late afternoon and evening hours, creating a consistent pattern of high-moisture activity that is not expected to subside until the end of May.

Geographic Vulnerability Increases Flash Flood Risks

The west coast of Peninsular Malaysia remains the primary target for these escalating weather events. Experts note that rainfall in this specific region usually reaches its peak during the April to May window, coinciding with the northward movement of the inter-tropical convergence zone. This seasonal shift significantly heightens the likelihood of flash floods in urban and low-lying areas. Recent incidents, including the collapse of a retaining wall in Kuala Lumpur and subsequent mud floods, underscore the immediate danger these concentrated downpours pose to local infrastructure and public safety.

Atmospheric Mechanics Driving the Tropical Rainfall Peaks

The current surge in moisture is linked to the North-South march of the inter-tropical convergence zone, a phenomenon explained by meteorologist Emeritus Professor Azizan Abu Samah. Unlike the east coast, which experiences a singular rainfall peak during the early north-east monsoon, the west coast endures two distinct peaks in April and October. This complex interaction of light winds and varying directions facilitates the rapid formation of massive thunderstorm clouds, leading to high-velocity winds and torrential rain over relatively short durations.