It's wet, wet, wet what's behind the rainy weather? -

A monsoon surge has been dumping rain on the island, with occasional strong wind gusts

- Shabana Begum

Cool weather rare for humid Singapore, flash floods, delayed flights and slow business.

All of these happened over three days starting from Jan 10, as a result of a monsoon surge that has been dumping rain on the island, with occasional strong wind gusts.

The mercury fell to 21.6 deg C in the Newton Road area on the morning of Jan 11, almost matching 2024's lowest temperature of 21.4 deg C.

A stretch of Jalan Seaview in Mountbatten was affected by flash floods on the evening of Jan 10.

Singapore is currently in the wet phase of the north-east monsoon, which typically lasts from December to January.

A monsoon surge that brings prolonged rain is a common phenomenon during this season.

The Straits Times explains the factors behind the prolonged deluge.

WHAT IS A MONSOON SURGE?

During the north-east monsoon, winds typically blow from the north-east to the south-west.

A monsoon surge refers to bursts of cold air from Central Asia.

When regions up north, such as Siberia, experience extremely cold weather in the winter months, the cold air occasionally sweeps southwards to the South China Sea, and is blown towards the tropics.

The air then warms and picks up moisture, leading to the formation of dense rain clouds. This brings increased rainfall near the Equator.

There could be moderate to heavy showers and thunderstorms in places such as Singapore, Malaysia and Vietnam. The rainfall can be prolonged - like it has been in Singapore since Jan 10 - lasting from two to several days.

The deluge on Jan 10 and 11 exceeded the amount of rain Singapore typically receives in the entire month of January.

Changi recorded the highest total amount of rainfall at 255.2mm over those two days, exceeding Singapore's monthly average rainfall of 222.4mm in January.