Northeast monsoon brings heavy rain, flash flood risks, and warm temperatures through month’s end
December is shaping up to be a soggy close to the year, with persistent wet weather set to affect daily routines, travel plans, and maritime activities across Singapore.
Persistent Showers Through Late December
The wet weather currently affecting Singapore is expected to continue through the rest of December due to prevailing northeast monsoon conditions, according to the Meteorological Service Singapore (MSS) on Dec 16. Thundery showers are forecast on most days, typically developing in the afternoon and extending into the evening on some days.
Risk of Widespread and Heavy Rain
MSS warned that showers could be widespread and heavy on a few days, although total rainfall for the second half of December is expected to be near average across most parts of the island. Despite frequent rain, daily maximum temperatures are projected to remain high, ranging between 32 degrees Celsius and 34 degrees Celsius.
First Half of December Set the Tone
The first fortnight of December already saw frequent moderate to heavy thundery showers across Singapore. On Dec 4, Jurong West recorded 134.2mm of rainfall, the highest daily total for the first half of the month. Most areas experienced above-average rainfall, with Jurong Pier recording 175 percent above average, while MacRitchie Reservoir saw slightly below-average levels.
Flash Flood Incidents and Warnings
Heavy rainfall during the first half of December led to several flash floods, including incidents in Kembangan and along East Coast Road on Dec 12. National water agency PUB issued multiple flash flood warnings, while the National Environment Agency (NEA) issued heavy rain warnings on seven days during the same period, highlighting the intensity of the downpours.
Warm Temperatures Despite Rain
Despite the persistent wet conditions, temperatures have remained relatively high. The highest daily maximum temperature of 34.5 degrees Celsius was recorded at Newton on Dec 5, consistent with readings seen throughout the month. MSS noted that warm and humid conditions are typical during the northeast monsoon season.
Maritime Advisory in Effect
The Maritime and Port Authority of Singapore (MPA) has advised sea users to remain vigilant, as the northeast monsoon is expected to persist until March 2026. Stronger winds, choppier sea conditions, and periods of moderate to heavy rain may affect maritime operations and recreational activities.
The extended spell of wet weather underscores the growing importance of climate preparedness in Singapore and the wider region. With flash floods, maritime risks, and transport disruptions becoming more frequent, coordinated responses and public awareness remain crucial for both Singaporeans and neighboring communities in Indonesia that share similar monsoon patterns.
Sources: Asia One (2025) , Straits Times (2025)
Keywords: Singapore Rainfall, Northeast Monsoon, Thundery Showers, Flash Flood Warnings, Meteorological Service Singapore
