Access to water, sanitation, and hygiene (WASH)-including drainage-services-is essential for public health and socio-economic development, but access remains inadequate and inequitable in low- to middle-income countries such as South Africa. In South Africa, rural areas and small towns generally depend on a limited and climate-sensitive economic base (e.g., farming), and they have a limited capacity and are located in areas where transport challenges can increase WASH access risks. Climate change shifts hydrological cycles, which can worsen WASH access and increase susceptibility to the interlinked impacts of droughts and flooding in already vulnerable regions. We adopted a transdisciplinary approach to explore the needs, barriers, and vulnerabilities with respect to WASH in rural areas and small towns in South Africa-using two case studies to explore climate risk and vulnerability assessment (CRVA) in one rural village in the northern Limpopo province and a small town in the Western Cape province. This holistic approach considered natural (environment and climate) and socio-economic (economic, social, governance, and political) factors and how they interplay in hampering access to WASH. Extreme weather events characterized by frequent and intense droughts or floods aggravate surface and groundwater availability and damage water infrastructure while threatening agriculture-dependent livelihoods. The lack of reliable transport infrastructure increases risks posed by flooding as roads to vital supplies are prone to damage. High inequality linked to rising unemployment and the Apartheid legacy of a segregated service delivery system result in inequitable access to WASH services. The intertwined ways in which natural elements and historical, social, economic, governance, and policy aspects are changing in South Africa increase WASH vulnerability in rural areas and small towns.