The study analyzes a direct relationship between solar radiation, temperature and an inverse relationship with rainfall and relative humidity and also sunshine. The study scrutinizes the reliability and validity of existing analysis that focus on the various environment factors on photovoltaic (PV) system's performance for the first time four environmental factors (temperature, relative humidity, rainfall and sunshine). Affecting the system performance are investigated simultaneously. The study area is Southern Delta University, Ozoro. Ozoro is the Headquarters of Isoko North Local Government Area of Delta State, Nigeria. During the dry season (October -March), the average temperature in Rainfall in Delta State Polytechnic Ozoro ranged between 26.48 - 27.790C and in rainy season (April - September), the average monthly temperature ranged 25.01 27.150. Temperature in Ozoro is low at night and high in the day as a result of the external heat supply by the sun.