Climate change, with effects on temperature and rainfall, has a great influence on dry period. Therefore, it is very important to study this phenomenon in the analysis of dry period length. In this study, we used GFDL-ESM2M and four RCP scenarios to simulate precipitation, maximum and minimum temperature and used CCT with statistical methods to downscale the results. The data used in this study were obtained from synoptic, rain gauge and evaporation stations. The result were evaluated for the base period (1990- 2012) and near future (2020-2050). The model results were evaluated using R² and NS. In all stations R² and NS for precipitation, maximum and minimum temperatures were between 0.67- 0.99 and 0.61-0.98, respectively. After evaluating and ensuring the suitability of the model, we simulated precipitation, and maximum and minimum temperatures and analyzed drought periods. The results indicated that precipitation increased in all scenarios, except in the southern areas in Kerman Province. This increases reached up to 60 percent in some areas. In the south however, a decrease of between 10% and 40% was predicted. Also, maximum temperature increased in all scenarios. In RCP 2.6 and RCP 8.5 scenarios we predicted temperature increases of 2 and 4 degrees on average. Despite lower temperatures the northern region will experience longer drought periods. Drought periods of more than 200 days will become more frequent in the south. Thus, this area requires special attention to the use and storage of water resources.