Abstract Physics includes the study and investigation of the phases that make up the hydrological cycle, including the estimation of flow rates in river basins, most of which are not instrumented, i.e ., they lack historical records of circulating flows. For this situation, the application of hydrological models can allow flow estimates to be made. In the Department of Norte de Santander, Colombia, some watersheds do not have instrumentation for flow measurement or hydrological modeling methodologies appropriate to the site. Therefore, methods such as the modified rational model of Teméz are used, even without knowing the relevance of its applicability to the site conditions. Consequently, for the present research, the Teméz model was validated in watersheds of the Norte de Santander Department to estimate the values of extreme flows with a return period of 100 years. In this sense, 11 watersheds were selected, which contained historical rainfall data greater than 20 years and a drainage network of fewer than 1000 Km 2 . It was found that the Teméz model overestimates the real flows of the 11 hydrological basins, where the climatological parameters used in the application of the Fhrüling factor and its statistical verification using multivariate regression did not achieve an acceptable correlation.