Climate change intensifies extreme weather events, threatening agriculture, water security, and socio-economic stability in semi-arid regions. This study projects 25 extreme climate indices for the Moghan Plain, Iran, using 1993-2014 data as baseline and bias-corrected outputs from eight CMIP6 models under SSP1-2.6 and SSP5-8.5 scenarios for 2021-2100. The three best-performing models (CanESM5, INM-CM5-0, and MPI-ESM1-2-LR) were selected for the ensemble based on superior skill scores. Trends were evaluated with the Mann-Kendall test and Sen's slope estimator, and uncertainty was quantified via bootstrap resampling. Results indicate a shift toward a hotter, more hydrologically stressed climate. Precipitation extremes intensify but become episodic: heavy rainfall indices (Rx1day + 5-6 mm, Rx5day + 1-3 mm, R95p + 7-8 mm, R99p + 2-3 mm, SDII, R10mm, R20mm) increase, while consecutive wet days (CWD) decline slightly (from 3.55 to 3.37-3.33 days/year) and consecutive dry days (CDD) lengthen significantly (from 60.77 to 61.72-66.15 days/year). Temperature extremes show strong warming: warm indices (TXx+ 1.8 to + 4.5 degrees C, TNx+ 1.1 to + 3.0 degrees C, SU25, TR20, TX90p, TN90p) rise markedly, cold indices (FD-23 to-36 days, ID, TX10p, TN10p, CSDI) decline sharply, and growing season length (GSL) extends (from 314.9 to 335.6-352.1 days). Diurnal temperature range (DTR) changes marginally. Uncertainty is higher for precipitation than temperature extremes and increases under SSP5-8.5. These shifts heighten risks of heat stress, drought, flash floods, and agro-climatic changes. Region-specific adaptation (e.g., integrated land-water management) is essential to enhance resilience in this vulnerable agricultural region.