Freshwater systems and frozen terrains are integral to Earth's climate regulation, ecological stability, and human survival. In the domain of hydrology & cryosphere, researchers delve into the complex hydrological cycles that govern river basins, aquifer systems, glaciers, and permafrost. This field not only addresses surface and subsurface water dynamics but also investigates the evolving behavior of snowpacks, ice sheets, and sea ice in response to climatic fluctuations. Recent studies highlight alarming rates of glacial retreat, altered runoff patterns, and thawing permafrost releasing greenhouse gases—each with cascading impacts on water availability, biodiversity, and sea level rise. With advancements in remote sensing, hydrological modeling, and isotope hydrology, new insights are emerging into the coupling between frozen water reservoirs and global climate systems. The focus on Hydrology & Cryosphere is crucial for crafting adaptive water resource strategies and anticipating shifts in seasonal water cycles across vulnerable regions.