Based on numerical simulations performed with the WRF model for a frost event in Southern Brazil in July 2013, it was possible to test different physical parameterizations and evaluate these parameterizations in these weather conditions. Although the results do not show considerable statistical differences, the experiment utilizing the Dudhia for shortwave radiation, RRTM for longwave radiation schemes, WSM6 for microphysics and YSU for boundary layer showed better results in the frost event, as it had the lowest values of ME and RMSE for the minimum temperature, relative humidity and wind speed. However, it was not possible to determine which parametrization produce the largest impact from these experiments. A greater number of frost events must be simulated with WRF model in order to obtain a more robust statistical analysis.