The scarcity of long time-series of water temperature for tropical reservoirs, usually available at a low frequency of measurements, represents a serious constraint for the understanding of their thermal behavior. Hydrodynamic models become a powerful tool for that understanding through a qualitative approach. In this study, the one-dimensional General Lake Model (GLM) was applied to hindcast multiannual temperature profiles of a cascade system of six reservoirs located in southeast Brazil over a period of eight years. The model parameters were calibrated and validated by field data for four reservoirs. To overcome the challenge of exploring hydrodynamics in two reservoirs with a lack of measured temperatures, a parameterization strategy was applied to accomplish a better simulation by the estimation of potential sensitive parameters through regression curves. It is expected that this approach can be extended to other tropical reservoirs whenever field data is not available for the calibration procedure.