In low-latitude cities like Singapore, urban heat islands contribute to the urban dweller’s summer discomfort and significantly increased air conditioning loads. This study investigates the key factors causing urban heart island in Singapore. The possibilities of improving heat extraction rate by optimizing air flow in selected hot spots were explored.  The effect of building geometry and the location of air conditioning condensers on the outdoor air temperature was investigated using Computational Fluid Dynamics (CFD) simulations. It was found that strategically placing a few blocks of high-rise towers will actually help to enhance the velocity within the canyon thereby reducing the air temperature. Air conditioning units spaced widely apart do not contribute much to the heat built up inside a canyon when the geometry is simple and as long as there is some wind flow within the canyon.