Singapore can expect more rainy days ahead during the coming Northeast Monsoon season between mid November this year and end January next year, according to the National Environment Agency’s (NEA) Meteorological Service Singapore.


The Northeast Monsoon season is characterised by short-duration thundery showers mainly in the afternoon and evening, and about two to four episodes of monsoon surges. Monsoon surges refer to the steady strengthening of northeasterly winds blowing from the South China Sea. These monsoon surges usually bring periods of prolonged widespread moderate to heavy rain lasting between two to five days, occasionally windy conditions, and cooler temperatures. 

On average for Singapore, there are 19 rain days each in November and December, and 15 rain days in January. The prevailing weak La Nina in the Pacific Ocean could contribute to a wetter than usual Northeast Monsoon season this year. 


Enhancing operational preparedness


In preparation for the Northeast Monsoon, PUB has stepped up efforts in drainage maintenance and monitoring. PUB advises the public to exercise caution as flash floods may occur in the event of heavy storms. 


To enhance monitoring efforts, PUB is expanding the network of sensors to track water levels at various drains and canals. More water level sensors are being installed and this will bring the total number of sensors from the current 93 to 150 by the end of the year. 


PUB has also stepped up its drainage maintenance regime to keep the drains flowing and minimise the risks of flash floods. This includes increasing the frequency of inspection and cleansing, especially in the flood prone areas and areas where there is high pedestrian traffic and litter, and roads densely planted with trees with heavy leaf falls. PUB has also stepped up inspections at major construction works, to check for obstructions in the drains and to ensure that there is no discharge of silt water.


A new initiative that PUB is rolling out is the installation of CCTVs at flood-prone areas. Currently, six CCTVs are installed along Bukit Timah Road as part of a trial to allow PUB to remotely monitor the situation in this area during heavy rain. These include outlet drains and low-lying spots which might experience flash floods during intense storms. Having these CCTVs will allow PUB to monitor real-time site conditions and respond even faster. Following this trial, PUB is expanding this initiative and will be installing 55 CCTVs in other flood prone areas in Singapore. The installation of these CCTVs is expected to complete by early December 2011.


Drainage Improvement Projects


PUB has an ongoing drainage improvement programme to alleviate flooding in the flood-prone areas. PUB recently completed improvement works at Kelantan Road that will help alleviate flooding at Veerasamy Road and Hindoo Road. The raising of Orchard Road (from Orange Grove Road to Cairnhill Road) has also been completed. At the MacPherson area, the reconstruction of an outlet drain near Lorong Bakar Batu Road was completed in September 2011. The completed works will provide additional flood protection at these areas.


Improvement works are also currently being carried out in areas including the Bukit Timah Canal (from Maple Avenue to Jalan Kampong Chantek), Geylang River (from Guillemard Road to Dunman Road), Rochor Canal (from Jalan Besar to Crawford Street), Alexandra Canal (from Zion Road to Kim Seng Road), as well as areas in MacPherson and Little India. A list of recently completed, ongoing and upcoming flood alleviation projects is available at this URL:


Public Preparedness


Ahead of the monsoon season, PUB has distributed flood advisories to 294 residential units and shop-houses in the central, western and eastern regions. These are low-lying areas, some of which are also subject to tidal influence. Besides informing them of the possibility of flash floods, information on the precautions they could take to protect their belongings is also provided. 


PUB is also working with building owners on the measures that they could implement to provide additional protection for their premises. For instance, Liat Towers and Tong Building have installed flood gates. 


Keeping the public informed


Besides the regular weather forecast, NEA will issue warnings through the media when heavy rain is expected. This will help the public to better prepare for heavy rain.


PUB has opened its water level SMS alert system for public subscription since 1 July 2011. Members of the public who want to keep tabs on the water level in a canal or drain at a designated location can subscribe to this alert service. Subscribers will receive progressive SMS alerts if the water level in the selected canal rises above or falls below stipulated levels of the canal’s depth. The Water Level SMS alert service is part of the Integrated Heavy Rain and Water Level Alert Service jointly operated by NEA and PUB. Members of the public can subscribe to either or both alerts at PUB’s website


The public can also access the water level information at PUB’s website at and get updates on water level information and flash flood alerts on PUB’s Facebook Page: or Twitter:


The latest weather reports, including heavy rain warnings, are available through:

        NEA’s iPhone App (myEnv)  

        NEA’s mobile weather service at Weather@SG ( 

        Twitter via @NEAsg

        the weather forecast hotline at 6542 7788 

        radio broadcasts


In the event of flash floods, the public can tune in to radio broadcasts or call PUB’s 24-hour Call Centre at 1800–284 6600 to report incidents or to check the flood situation. 


To facilitate public access to information on the most recent flash flood incidents, PUB has posted updates on its website: