The goal of this study is to examine whether the “evaporation paradox” is still true by investigating the response of ET0 to changing climatic environment based on recently updated nationwide observation in China. Specifically, we begin by identifying the homogenously sensitive regions of ET0 using a rotated empirical orthogonal function clustering method. Then we assess the spatial patterns of ET0 trends and analyze the abrupt change in average series for individual homogenous regions. Meanwhile, special efforts are further made in characterizing the underlying aerodynamic and radiative driving mechanism for the ET0 changes. Finally, the driving mechanisms under natural large atmosphere system are explored by identifying the correlation between changes in ET0 and Pacific Decadal Oscillation.