Drought appears as an environmentally integral part of climate change. This study was conducted to investigate the impact of climate change on climate variables, meteorological drought and pattern recognition for severe weather conditions in the Karkheh River Basin in the near future (2043-2071) and the distant future (2072-2100). The outputs of GFDL-ESM2, HadGEM2-ES, IPSL-CM5A-LR, MIROC and NoerESM1-M models were downscaled under the RCP 2.6 and RCP8.5 scenarios using the Climate Change Toolkit (CCT) at 17 meteorological stations. Then the SPEI index was calculated for the base and future periods and compared with each other. The results showed that the basin annual precipitation will likely increase in both future periods, especially in the near future. The annual maximum and minimum temperatures may also increase especially in the distant future. The rise in the maximum temperature will be possibly greater than the minimum temperature. Seasonal changes in maximum and minimum temperatures and precipitation indicate that the greatest increase in temperature and decrease in precipitation may occur in summer. Hence meteorological drought was also found to increase in the distant future. The application of the CCT model in the region showed that at least once a wet period similar to the flood conditions of 2019 will be observed for the near future. There will also be at least one similar drought in 2014 for the distant future in the region. However, in previous climate studies, future events have not been calculated based on identifying the pattern of those events in the past.