Numerical Weather Prediction (NWP) models are treated as helping tools for the weather forecasters in this era ofscience and technology. Generally Evaluation of NWP models is made to gauge the level of reliability in particular region as well as phenomena of specific weather pattern. As Pakistan is an agricultural country and precipitation isbasic ingredient for agriculture and in Monsoon season it receives more than 60 % rain of the total annual rain.Therefore precise forecasts are believed to be assurance for successful agriculture with sufficient lead time. A hydrostatic NWP model HRM containing 40 vertical model layers and 7 soil layers, is evaluated at horizontalresolution of 22km and 11km for the prediction of precipitation in South Asian Monsoon season. Four rainfall events of different intensities are simulated at 00UTC by HRM at both selected horizontal resolutions with domain7°-45°N latitudes and 55°-96°E longitudes. The model simulated rain has been compared with actual rainfall and Analyses of this study show that the performance of HRM with horizontal resolution 22km is better than that of 11km for Monsoon season. The results of extreme rainfall events (28-29 July, 2010) also indicate that the model HRM has good capability to estimate rain over Pakistan region whereas less capability of estimating rain has been observed for 21st July and 8th August, 2010. Further, variation in spatial extent of precipitation regime has beenobserved from simulations at both grid scales.