Shah Alam sits on Peninsular Malaysia’s west coast, where a wetter southwest monsoon and frequent convective thunderstorms combine to make rainfall a near-constant feature of the equatorial climate, with flash flooding the region’s primary weather hazard.
Selangor’s state capital sits on a flat plain where drainage capacity, rather than terrain, is the main factor in local flood risk. Rapid urbanization has reduced natural drainage capacity across much of this densely populated corridor, so even a routine afternoon thunderstorm can cause serious street flooding within minutes, which is why Malaysia’s Meteorological Department relies heavily on radar for short-term flood warnings here. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map