Lakes are critical natural resources. In a warmer climate, lake evaporation is projected to increase globally while water inflow into lakes may increase or decrease under regional hydroclimate change, making it unclear how regional lake volumes will respond. Here, by using a reformulated Penman equation to interpret the model-projected lake evaporation changes, we show that the spatial pattern of future lake evaporation increase is coupled to regional hydroclimate change. Specifically, a drier future hydroclimate will amplify lake evaporation increase by enlarging surface vapor pressure deficit and reducing cloud shortwave reflection. Such spatial coupling between regional hydroclimate change and lake evaporation increase indicates qualitatively robust changes in regional lake volumes. Specifically, In tropical America, the Mediterranean and Southeast China, lakes will likely shrink as drier future hydroclimate concurrently enhances lake evaporation and reduces water inflow. In high latitudes and Tibetan Plateau, lakes will likely expand as wetter future hydroclimate dampens and overcompensates for lake evaporation increase. Therefore, lake volume responses can aggravate water scarcity or flood risks induced by regional hydroclimate change.