The population in Sub-Saharan Africa is regularly affected by droughts, such as those recently triggered by El Niño. Rural smallholders in semi-arid environments such as the transnational Cuvelai Basin in southern Angola and northern Namibia directly depend on local blue and green water availability and are therefore at risk of drought. This study builds on local knowledge of seasonal water and food consumption patterns to estimate household drought sensitivity. An empirical survey was conducted with 461 households to (1) determine the reliability of water and food source types under dry conditions, (2) estimate consumption dependencies, and (3) contribute to drought risk assessments. The consumption patterns reveal differences in the reliability of source types. In particular, traditional types are used extensively during the rainy season but become unavailable during the dry season. Households with a strong dependence on these types are particularly sensitive to drought. This is true for rural areas, notably in Angola, where reliable water and food infrastructures are less available. This methodology can be implemented in conventional surveys to continuously monitor drought sensitivity conditions on the household level.