The National Climatic Data Center (NCDC) is mandated by the National Oceanic and Atmospheric Administration to perform data management functions of acquisition, quality assessment, archive and dissemination services for the nations meteorological/climatological data. The primary variable used by the largest spectrum of users is temperature. This paper describes the quality assurance procedures that are applied to both hourly and daily temperature data. This includes discussion on: station internal consistency checks, extremes checks, climatology checks, spatial review and future quality assurance plans