The production of 222 Rn depends on the activity concentrations of 226 Ra in the earth's crust, in soil, rock and water. Radon concentration levels are strongly affected by atmospheric influences such as rainfall, real humidity, temperature and barometric pressure, rather than by chemical processes, as it is an inert gas. In particular the exhalation of radon is positively correlated with moisture content, temperature and negatively with pressure, so that these factors must be considered in the determination of exhalation rates in environmental measurements. In this study, radon concentrations in soil gas were continuously monitored for nine months in ten minutes periods, using AlphaGUARD system and the fluctuations of radon concentration were compared with the regional meteorologic data, using time graphs.