The impact of rainfall and temperature on agricultural crop production, especially cocoa and cassava in Nigeria, has significant implications for yield, poverty, access to food, and the sustainability of farming as a livelihood. This study investigates the influence of temperature and rainfall on cocoa and cassava yield in Ondo State, Nigeria, from 1991 to 2020. The annual crop yield data for cocoa and cassava for the entire 30-year period were sourced from the Ministry of Agriculture, Ondo State. Data for the key climate variables, temperature (maximum and minimum), and rainfall, were obtained from the Nigeria Meteorological Agency (NIMET). Initially, a line graph was employed to visualize trends in rainfall, temperature, cocoa, and cassava. Subsequently, the data was subjected to K-Means clustering analysis, to partition rainfall, maximum and minimum temperature into distinct and meaningful groups, or cluster, based on the similarities between the years – identifying patterns and structures to reveal hidden relationships and groupings among the years. The collected yield datasets were further grouped by the cluster, an analysis of variance (ANOVA) was further performed to test the influence of each weather variables has on cocoa and cassava yield. The trend analysis revealed that Ondo State experienced minimal temperature fluctuations between 1991 and 2020, while rainfall and cassava exhibited distinctive fluctuations. The results confirmed the significant impact of temperature and rainfall on cocoa and cassava yield.