This research investigates the effects of temperature and relative humidity on UHF radio wave signals. A spectrum analyzer was used in measuring UHF signals while a digital thermometer and hygrometer was used in measuring temperature and relative humidity, respectively. From results obtained, relative humidity had no effect on UHF signal strengths while temperature had a positive correlation effect on path losses in UHF radio waves. This implies that an increase in temperature will lead to a decrease in received signal strength of UHF signals. Furthermore, a path loss propagation model for Calabar was obtained using multiple regression analysis and we believe that the result obtained in this study will be useful to radio engineers, for UHF signal propagation in the study terrain.