EN
Temperature, rainfall, vapour pressure, diurnal temperature range (DTR), relative humidity, and other climatic variables have all been connected to the transmission and spread of diseases like diarrhoea, Tuberculosis (TB), and typhoid. However, the complicated interactions between these climatic variables and illness incidence remain poorly understood. This study examined the interactions between climatic variables, diarrhoea, Tuberculosis (TB), and typhoid in the selected South-South States, Nigeria. To achieve this, annual rainfall, temperature, vapour pressure, and diurnal temperature range (DTR) were employed using the ex-post facto research approach. The data on diseases were extracted from the various states' Ministry of Health for the period 1962 - 2021. The correlation results showed that there was a significant but moderate positive relationship between rainfall and diarrhoea, r [360] = [.345], p = [< .001]. DTR had a weak and negative significant relationship with diarrhoea, [-.266], p = [< .000]. While vapour pressure and temperature had a significant but weak positive relationship with diarrhoea, [.290], [.258], p = [< .000] respectively. The regression results showed that there was a significant but weak negative relationship between rainfall and typhoid, r [300] = [-.292], p = [< .000]. Vapour pressure and DTR had a weak positive significant relationship with typhoid, [.149], [.152], p = [< .000], p = [< .008] respectively. While temperature had a significant but moderate positive relationship with diarrhoea, [.290], [.369], p = [< .000] respectively. To mitigate the effects of diseases, Nigerians are advised to strengthen their safe-drinking water, sanitation, and hygiene (WASH) systems.