The Arctic Rapid Integrated Monitoring System (ArcticRIMS) uses products from numerical weather prediction models (NCEP/NCAR, ERA-40, station records, satellite remote sensing, and other data sets) in conjunction with an atmosphere-land surface water budgeting scheme. The geography and dynamics of water across the pan-Arctic region are important elements of the larger Earth system especially given growing evidence of the vulnerability of the Arctic climate and terrestrial biosphere to global change. The Arctic freshwater cycle figures prominently into any analysis of these dynamic systems. In addition to historical time series, updates are compiled of various gridded fields. These include precipitation, evapotranspiration, soil moisture, soil freeze/thaw state, active layer thickness, snow extent and its water equivalent, soil water storage, runoff and simulated discharge. Products are periodically refined as improved data sets and techniques become available.