Science and Facts

Cooling Singapore works on furthering our understanding of the Urban Heat Island effect (UHI) as it applies to Singapore, and systematically assessing the simulation tools and potential strategies that can be used to mitigate UHI and improve outdoor thermal comfort (OTC). Key tasks include identifying the sources of energy and its losses in Singapore, modelling the UHI effect, and investigating anthropogenic heat released from buildings and road traffic, as well as publishing reports and guides.



Meso-scale UHI Simulations

The WRF model was used to analyze the impact of UHI for April (the inter-monsoon season) when the UHI intensity in Singapore is expected to be at its highest. The key findings for Singapore include that the UHI effect can be as high as 4.2ºC during night time. The mitigation measures evaluated through WRF suggest that: 

  1. Using high reflective materials for roofs can lower the temperatures by about 1.47ºC 
  2. A 20 % reduction in energy can be achieved by increasing the thermostat set temperature in commercial buildings by 4ºC.
  3. Increasing building density can adversely affect ventilation and thermal comfort, and blockage of major breezeways should hence be avoided for developments planned for 2030. 

WRF modelling and simulations can support the mitigation of UHI and help propose countermeasures to offset the impact of UHI in Singapore. The impact of UHI is of particular interest to URA for existing and future developments. Further improvements in the modelling effort are currently underway and will help to develop a strong UHI mitigation framework.