The Yarlung Zangbo River Basin, located in the southeastern Qinghai–Tibet Plateau, is an important transboundary river system in China. The basin features dramatic topographic relief, forming a unique vertical climate spectrum. To evaluate the accuracy of temperature, air pressure, wind speed, and relative humidity from three reanalysis datasets (ERA5-LAND, TPMFD, and CDMet), the ground observations at three sites in that basin (including Nam Co, Mount Qomolangma, and Southeast Tibet Alpine site) are selected as the references. Results show that each dataset has distinct advantages. TPMFD demonstrates the highest consistency for temperature at both daily and monthly scales, with R² values generally above 0.9 and relatively low RMSE, respectively. CDMet performs best in representing relative humidity, with R² of 0.53 and RMSE of 10.8%, respectively. CDMet performs relatively better in representing wind speed compared to the other two products; however, due to the strong influence of complex terrain, it still exhibits substantial errors and uncertainties. The coefficients of determination (R²) at the three sites are 0.1825, 0.1043, and 0.0514, indicating poor agreement with observations. ERA5-LAND shows the best performance in atmospheric pressure, with R² values of 0.9148, 0.8339, and 0.9429 at the three sites, demonstrating high consistency and reliability. These findings provide an important reference for selecting appropriate meteorological reanalysis datasets in hydrological and ecological studies across the Tibetan Plateau and other high-altitude regions.