The monsoon season is the primary driver of flood risk. Historically, Singapore relied on concrete canals. However, the "design storm" criteria (the amount of rain a drain is built to handle) are being challenged by the new intensity of monsoon rains. Flash floods are becoming more common in urban pockets where drainage capacity is exceeded.
The is not a single rainy season, but a series of distinct weather patterns that dictate the island’s tropical rhythm. Because Singapore is located just 1.5 degrees north of the equator, it doesn't have four temperate seasons. Instead, its climate is defined by the Northeast Monsoon , the Southwest Monsoon , and the two Inter-monsoon periods that bridge them. monsoon period singapore
While total annual rainfall has not changed drastically in volume, the intensity has increased. The warming atmosphere holds more moisture (Clausius-Clapeyron relation), leading to more frequent "high-intensity short-duration" storms, particularly during the inter-monsoon periods. This challenges the traditional understanding of monsoon predictability. The monsoon season is the primary driver of flood risk