The use of site diversity as a mitigation technique to minimize the adverse effect of rain attenuation on microwave links above 10 GHz is investigated. The work presents the analysis of weather radar and beacon data for the simulation and performance evaluation of site diversity system in South-East Asia. The impact of link parameters on site diversity technique such as site separation distance, elevation angle, frequency of operation and baseline angle is examined. The results obtained are compared with some existing site diversity prediction models. The results show that site diversity gain depends heavily on site separation distance and elevation angle while less dependence is observed on frequency and baseline angle of the site diverse stations. The comparative studies show that all the three existing models considered underestimate site diversity gain at all separation distances except Hodge model which underestimates at site separation distance of 10 km and above.