The Northeast monsoon, which is likely to persist until March 2026, may at times bring stronger winds, choppier sea conditions, and moderate to heavy rain. The Maritime and Port Authority of Singapore (MPA) advises members of the public, port users, and maritime industry stakeholders to stay alert, exercise caution at sea, and ensure that appropriate personal safety measures are in place and vessels are properly prepared for sea during this period.

I. MSS Forecast

According to the latest forecast from Meteorological Service Singapore (MSS), low-level winds over Singapore and the surrounding South China Sea region began to strengthen and veer around late November 2025, blowing from the northwest or northeast – heralding the start of the northeast monsoon season. The monsoon is now in its wet phase; cloudy, rainy and occasionally windy conditions are expected to persist through January 2026. During this period, converging winds over Singapore and nearby areas can trigger afternoon and evening thunderstorms, and monsoon surges – reach typically lasting two to three days – may bring brisk northeasterlies and prolonged rain. From February to March 2026 the monsoon is forecast to enter its dry phase: the rain-band shifts south of the equator, reducing the number of rainy days and allowing temperatures to rise. Intense daytime solar heating over land can then set up sea-breeze circulations, causing wind convergence over Singapore and localized thunderstorms in some areas.

 II. Impact on Ships

1. Sudden downpours reduce visibility on approach and shrink the safety margin while under way.
2. Persistent monsoon winds drive the vessel bodily to leeward and impose a yawing moment, degrading directional stability.
3. A rapid increase in wind strength, especially violent gusts, can strike unexpectedly and raise the difficulty of maneuvering.
4. Accelerated currents generated by the monsoon make it harder to maintain position, both for ships transiting the Singapore Strait and for those at anchor.
5. Strong on-shore winds can push a berthed vessel off the wharf, opening a gap that endangers gangway safety (particularly for passenger ships) and risks damage to accommodation ladders or hull structures.
6. Tight alongside spacing in berths can cause mooring lines to be chafed in wind and swell, increasing the likelihood of collision with adjacent ships or contact with the quay or port equipment.
7. Gusts hamper cargo operations, cut terminal productivity and aggravate port congestion.
8. Reduced visibility and rougher seas brought by monsoon rain plus the persistent piracy threat in the Singapore Strait, compound security pressures on merchant shipping.

III. Advice to Members

The Singapore Strait – one of the world’s busiest choke-point – is characterized by narrow fairways, strong tidal streams, high traffic density and complex crossing situations. Members are therefore advised to exercise caution during the monsoon season and implement the following precautions:

1. Check MSS weather forecasts and tidal conditions; monitor monsoon updates and make voyage plans accordingly.
2. Before entering the Strait, the master should arrange a full check on critical equipment – main engine, steering gear, anchors, radars, AIS and all other navigational aids – to confirm they are in good working order.
3. When navigating within the TSS, maintain a safe distance from vessels ahead and astern. If sudden squalls or heavy rain are encountered, reduce speed and alter course in advance.
4. Masters should ensure that crew maintain a proper lookout in restricted visibility caused by rain and keep the anchor ready to improve emergency response.
5. Inspect all mooring gear; add extra lines where necessary and re-adjust tension to suit tidal and wind changes.
6. While alongside, disembarkation procedures should be adhered to and keep sufficient personnel on board.
7. Secure all cargo, lashings and accommodation ladders before every voyage to prevent injuries or damage from vessel motion.
8. Recognize that heavy weather can impair target identification on radars; increase lookout and patrols on the main deck to deter pirates who may exploit low visibility.

For more information, please contact Managers of the Association.

Attachments:

File	File size
Staying Safe at Sea during the Monsoon Season 2025.pdf	172 kB
LP222025 MPA Alert Staying Safe at Sea during the Monsoon Season 2025.pdf	346 kB