Oceans are expected to bring their maritime influence to coastal zones, and sometimes further inland, to affect the terrestrial energy and moisture fluxes. Heat and water balances jointly govern northern hydrology, both directly through the hydrological cycle and indirectly through cyclogenesis and radiation regimes. Drawing upon reported examples, a survey is presented to examine the roles of ocean currents, onshore winds, coastal storms and sea ice in modifying precipitation (snow, fog, orographic precipitation), evaporation (through radiation and moisture availability) and coastal inundation processes. Coastal currents can alter permafrost distribution on a regional scale and runoff patterns may be modified accordingly. There are also notable feedback mechanisms whereby hydrology affects oceanography. Examples include freshwater discharge that exerts influence on thermohaline circulation in polar seas and on the dynamics of coastal sea ice, and the export of sediments, organic carbon and nutrients to the Arctic Ocean. Given the sensitivity of high latitudes to climate warming, which impacts many aspects of the northern environment, collaborative investigations of ocean–atmosphere–hydrologic linkages are of priority interest.