Simulation models are important tools to explore and illustrate dynamics of climatic variables in crop based ecosystem. Two open-field experiments were conducted during 2015/2016 and 2016/2017 seasons at the Experimental Farm, Faculty of Environ. Agric. Sciences, Arish University (31° 08' 04.3" N, 33° 49' 37.2" E). This work was aimed to evaluate the performance of four bread wheat (Triticum aestivum L.) cultivars i.e.; Misr-1, Sakha-93, Giza-168 and Gemmeiza-9) in relation to two irrigation pattern i.e. surface supplemental irrigations (12 irrigations) and rainfed under the metrological conditions of North Sinai. Results obtained from experimental field studies were used as indicators to test the performance of DSSAT-CSM (Cropping System Model) Ver. 4.5.1.023. Necessary files were prepared as required. Two different climate scenarios have been implemented in order to study effects of future climate changes on wheat plant growth and yield. Scenarios were done by adding 2°C and 4°C to maximum and minimum temperatures of the last successful winter season (2016/2017) starting from the best sowing date indicated at conducted field experiments and finishing by the end of growing cycle. The future impacts of climate change on wheat showed that increasing in temperature will reduce length of growing cycle and the time needed to full tillering in addition to the final yield. This subsequently will reduce the amount of grain yield; accelerate time for maturity and harvesting. For +2°C scenario, reduction in grain yield, as predicted by the model, will be reach 9.6% loses in grain yield for supplementary irrigated Gemmeiza-9 cultivar and averaged of 18% among all other cultivars. Scenario of +4°C will reduce supplementary irrigated Gemmeiza-9 grain yield by 16.2% and within an average of 23.8% among all other cultivars. The reduction will be more under rainfed irrigation pattern. Generally, Supplementary irrigated Gemmeiza-9 cultivar is recommended treatment to maximized bread wheat grain yield and as an adaption measure to reduce yield variability as affected by increasing of potential temperature scenarios under North Sinai environmental conditions and all similarity regions.