Increasing water stress on forests is emerging as a global phenomenon, resulting in the episodes of tree mortality, canopy die-offs and declines in ecosystem resilience, threatening the progress of global carbon neutrality. The role of tree functional strategies is pivotal in regulating forest ability to cope with water stress. To date, the species-level water stress strategies including closing leaf stomatal early, investing in stronger water transport structures, dropping leaves, storing water and developing deeper roots are well documented. However, how strategies found at the tree or species level scale up to characterise forest communities and their variation across regions is not yet well-documented. By combining eight water stress-related functional traits with forest inventory data from the USA and Europe (219,518 plots), we investigated the community-level trait coordination and the biogeographic patterns of water stress strategies for woody plants, and analysed the relationships between the strategies and climate factors. We found that the range of water stress strategies which dominated at community-level were consistent with those available at species-level. Traits associated with acquisitive-conservative strategies formed one dimension of variation, while leaf turgor loss point, associated with stomatal water strategy, loaded along a second. Surprisingly, spatial patterns of local water stress strategies were better explained by temperature than by aridity, suggesting a greater selective pressure on water demand over supply. These findings provide a basis on which to build predictions of forest response under water stress which are grounded in the dominant functional strategy, with particular potential to improve understanding of forest carbon sink potential in a changing climate.