The study investigates the climate change impact on monthly and seasonal distribution of rainfall and temperature of three scenarios of the Intergovernmental Panel on Climate Change (IPCC) between year 2000 and 2099. The analysis considered two climatic periods which are 2000 to 2029 as present and 2070 to 2099 as future. The ten-year mean (decadal) analyses of these two parameters were also performed. The result showed that temperature increases over West Africa countries in all the months under each of the scenarios. Scenario A2 with the highest emission of 800 ppm shows the highest increase of temperature and rainfall over West Africa followed by scenario A1B with emission of 720 ppm and the least is that of B1 with the lowest emission of 550 ppm. The result also showed that rainfall increases over most part of West Africa in all the scenarios with the exception of coastline that a little decrease in amount of rainfall was estimated. However, the decadal analysis shows that there is a gradual and almost consistent increase in temperature and rainfall over West Africa. Monthly mean values of scenario B1 estimated higher in all the months than its scenario A1B counterpart while those of A1B are also higher than those of scenario B1. The result implies that the higher the emission, the higher is the temperature which leads to warmer future and most likely the more rainfall and hence likelihood of flooding, more occurrence of heat wave and other high temperature related problems. It therefore recommended that IPCC regulation to reduce emission should be strictly adhered to by all countries so that the world can have a better future to dwell in.