All living things are constantly exposed to background radiation. The presence of radioactive materials in the earth's crust and cosmic radiation are largely responsible for this exposure. The present study aimed to develop a new methodology of easy applicability and low cost to carry out measurements of environmental background radiation and to be able to establish a map of environmental radiation for primary monitoring of these exposures. For that, ionizing radiation measurements, Meteorological and Radiometric measurements were performed. Geiger Mueller Counter (GM) was used, as it is widely used in services that use radioactive sources and research centers. Measurements obtained showed that there were no statistically significant changes in the 24 hours of measurements with the GM, in relation to the variations presented in the Meteorological and Radiometric measurements that changed according to the time of day. The average value of the background radiation readings was 0.0194 mR/h, with an average variance of 1.8E-06 and an average standard deviation of 1.35E-03. GM proved to be useful for primary measurement of background radiation. The map was developed using open source libraries for the Python programming language. The map may be hosted on an open access website, so that professionals, students and researchers may contribute, sending new data from different locations. It is essential that the levels of radiation exposure are demonstrated and understood. Easy access to this information may contribute to health organizations, agriculture and research centers to establish a baseline for future research.