Rainfall variability and under-five child mortality in 59 low- and middle-income countries

Climate change is reshaping the Earth’s hydrological cycle. Such changes impact children’s health through multiple pathways. Here we show that, in 59 low- and middle-income countries, although sufficient annual rainfall decreases under-five child mortality, anomalies in seasonal rainfall could increase under-five mortality. The risk associated with rainfall scarcity (odds ratio 1.15, 95% confidence interval (CI) 1.11–1.20) was much higher than that associated with rainfall surplus (odds ratio 1.04, 95% CI 1.02–1.06). Extreme rainfall amounts and the number of wet days are positively associated with elevated under-five child mortality. These risks were more pronounced for children from rural areas, families with lower educational attainment and households that depend on natural water sources. From 2000 to 2020, rainfall variations, extreme daily rainfall events and the number of wet days are estimated to cause 290 under-five child deaths per 10,000 persons annually (95% CI 177– 417). This investigation provides important insights into the overlooked health consequences of rainfall pattern changes on vulnerable populations. Climate change is transforming the water cycle and impacting the availability of food and water—effects that are most severe in low- and middle-income countries, where they can impact child mortality substantially. Analyses of rainfall patterns indicate that although increased annual rainfall is associated with improved child survival, these benefits depend on seasonal stability and the absence of extreme weather events.