The data set compiled here consists of surface hydrographic data, including temperature and salinity, from the Laptev Sea. Data were collected during the summers of 1980 to 2000. The Arctic and Antarctic Research Institute (AARI) in St. Petersburg collected the data through a Russian-German collaboration. Researchers used different thermometers and salinometers during the study, with minimum accuracy within 0.05 degrees C or 0.05 psu. Temperature and salinity were measured within the surface layer (<1 m depth). Because of restrictions in the release of data within the Russian Exclusive Economic Zone (EEZ), and as specified in the original proposal, data have been interpolated to a regular grid. Data are in ASCII format.