The graduation thesis deals with the control of coordinates of the precipitation samplers, provided by the researchers from Jožef Stefan Institute and ARSO. Precipitation samplers at weather stations collect data of isotopes composition of precipitation. Display of precipitation samplers are not consistent in the Atlas okolja and Google Maps, so reliable weather station locations must be obtained. By transforming from the old to the new coordinate system and converting to the global coordinate system, we get the coordinates that we use to display and compare with the given coordinates. At two weather stations measurements were made to control the calculated coordinates.