Kielce University of Technology was a member of the international research project COST Action IC0802 – Propagation Tools and Data for Integrated Telecommunication, Navigation, and Earth Observation Systems, whose main goal was to analyze the impact of weather conditions on the quality of wireless satellite transmissions. Measurements in the region of Kielce city seem to be a good indication for rain rate exceeding the average year in Poland by 0.01%, especially due to a central location, environment, and morphology of terrain. Near the city since 1974 at Psary-Kąty was a large satellite ground station, operated by TP SA, with up to seven large parabolic antennae. The aim of this study was to present the rain rate (mm/h) exceeding the average year (R_0.01) in Poland by 0.01%. The part of results connected with measurements and data acquisitions and their processing for rain rate exceeding the average year by 0.01% is presented in this article. This R_0.01 parameter for Kielce was experimentally verified. Moreover, the R_0.01 parameters for the most important regions in Poland are also included in the article. On the basis of this we can predict, e.g., the availability of satellite systems within the whole territory in Poland to minimize the risk of lack or interruption of communications due to adverse weather conditions.