The TIROS-N Operational Vertical Sounder (TOVS) Polar Pathfinder (Path-P) data set consists of gridded daily and monthly Arctic and Antarctic atmospheric data derived from various NOAA satellites. TOVS Path-P daily files are available for the Northern and Southern Hemispheres from 60 degrees poleward at 100 km gridded spatial resolution in an Equal-Area Scalable Earth Grid (EASE-Grid). TOVS Path-P monthly files are available for the Northern Hemisphere only from 60 degrees poleward at 100 km gridded spatial resolution in EASE-Grid. Daily and monthly Northern Hemisphere data are available from January 1979 through current processing, and daily Southern Hemisphere data are available from July 1979 through current processing. Data were created from a modified version of the Improved Initialization Inversion Algorithm (3I) (Chedin et al. 1985), a physical-statistical retrieval method improved for use in identifying geophysical variables in snow- and ice-covered areas (Francis 1994).